Network Working Group                                       D. Smallberg
Request for Comments:  876                                           ISI
                                                          September 1983

                    Survey of SMTP Implementations

                         ---------------------- 

This memo is a survey of implementation status.  It does not specify an
official protocol, but rather notes the status of impementation of 
aspects of a protocol.  It is expected that the status of the hosts
reported on will change.  This information must be treated as a snapshot
of the state of these implementations.

                          ----------------------

     From May to August 1983, I tested SMTP servers on the Internet to
see whether they accepted connections from the Arpanet (a Class A
network) and ISI-Net (a Class B network), whether they accepted the user
"postmaster" as a mail recipient, and whether a nonexistent user was
immediately rejected as a mail recipient.

     The hosts from which the tests were conducted were ISI-VAXA on the
Arpanet (running 4.1bsd UNIX), and ISI-MOE on ISI-Net (running 4.1a).
Internet hosts were tested at various times throughout the last four
months.  During the survey, I noted anomalies in a few dozen hosts' SMTP
servers; examples included a RSET command causing the server to close
the connection, a VRFY POSTMASTER evoking a reply containing an illegal
mailbox, and some cases of improper reply codes.  These bugs were
reported and in most cases promptly fixed.

     I would class three problems as significant because about 40 hosts
exhibit at least one of them:

     1)  In reply to a RSET and/or a NOOP command, some servers reply
         "200", which is never a legal reply code, instead of "250".
         (See sections 4.2 and 4.3 of RFC 821.)

     2)  If a VRFY command occurs before a MAIL command, some hosts
         reply "554 Nested MAIL command".  The end of section 4.1.1 of
         RFC 821 states that a VRFY may occur anywhere in the session.

     3)  If a mail transaction is started, with a sender and receiver
         specified, and a RSET is issued before the text of the message
         itself is collected, some servers send a message to the sender
         about being unable to deliver mail because no message was
         collected.  While RFC 821 doesn't rule this out, it certainly
         is not consistent with the notion of resetting the transaction.

     In the table in the appendix, the names and addresses of the hosts
tested were taken from the NIC host table of 17 August 1983.  TACs and
echo hosts were not included in the survey.

Page 1

RFC 876

     Here are the summarized results of the survey:

483 hosts were tested

283 are claimed by the host table to support SMTP
 49 of those 283 (17%) failed to permit a connection to be opened from
      either ISI-VAXA or ISI-MOE.
 51 hosts did not claim to support SMTP, but did allow a connection to
      be opened from at least one of the two ISI test hosts.

285 hosts were connected to from ISI-VAXA
170 hosts were connected to from ISI-MOE; all 170 were connected to
      from ISI-VAXA as well.
115 hosts out of the 285 (40%), therefore, could be connected to from
      ISI-VAXA only.

 69 of the 285 connectable hosts (24%) returned a positive reply to the
      command "VRFY postmaster"

162 hosts out of the 285 connectable hosts (57%) immediately rejected
      mail addressed to a nonexistent user; that is, they gave an
      "unknown user" reply to the command "RCPT TO:",
      where "host" was the foreign host.
115 hosts out of the 285 (40%) gave a positive acknowledgement to a
      RCPT command with a nonexistent user.
  8 hosts (3%) were never up during this part of the test.

121 hosts out of the 162 which immediately reject mail to nonexistent
      users (75%) accepted mail for the recipient "postmaster".  Thus,
      42% (121 out of 285) of the connectable hosts do not immediately
      reject mail for "postmaster".

References:

RFC 821  Postel, J., "Simple Mail Transfer Protocol", RFC 821, Network
      Information Center, SRI International, Menlo Park, August 1982.

Page 2

RFC 876
                             APPENDIX

     The hosts in this table are taken from the NIC host table of
17 August 1983, with TACs and echo hosts omitted, and are grouped by
network.  There are six result entries for each host:

Claim SMTP    + = the host table lists this host as supporting SMTP;
              - = such support is not listed

Arpanet       + = a connection could be opened from ISI-VAXA
              - = no such connection could be opened

ISI-Net       + = a connection could be opened from ISI-MOE
              - = no such connection could be opened

VRFY Post     + = the command "VRFY postmaster" evoked a positive reply
              - = it did not

RCPT Post     + = the command "RCPT TO:" elicited a
                        positive reply
              - = it did not

Bad jqkx      + = the command "RCPT TO:" elicited a
                        negative reply (i.e. unknown user)
              - = it received a positive reply (i.e. recipient accepted)

Claim Arpa ISI- VRFY RCPT Bad
SMTP  net  Net  Post Post jqkx Host name            Address      Notes
----- ---- ---- ---- ---- ---- ---------            -------      -----
  -    -    -    -    -    -   alta-coma            3.1.0.50
  -    -    -    -    -    -   satnet               4.0.0.0
  -    -    -    -    -    -   etam-expak           4.0.0.1
  -    -    -    -    -    -   goonhilly-expak      4.0.0.2
  -    -    -    -    -    -   tanum-expak          4.0.0.3
  -    -    -    -    -    -   satnet-sink          4.0.0.37
  -    -    -    -    -    -   etam-monitor         4.0.0.41
  -    -    -    -    -    -   goonhilly-monitor    4.0.0.42
  -    -    -    -    -    -   tanum-monitor        4.0.0.43
  -    -    -    -    -    -   raisting             4.0.0.72
  -    -    -    -    -    -   raisting-monitor     4.0.0.78
  -    -    -    -    -    -   raisting-expak       4.0.0.79
  -    -    -    -    -    -   fucino               4.0.0.88
  -    -    -    -    -    -   fucino-monitor       4.0.0.94
  -    -    -    -    -    -   fucino-expak         4.0.0.95
  +    +    +    -    +    +   bbncca               8.0.0.2
  +    +    +    -    +    +   bbnccb               8.1.0.2
  +    +    +    -    +    +   bbnccc               8.2.0.2
  +    +    +    -    +    +   bbnccd               8.3.0.2
  +    +    -    -    +    -   bbnccg               8.0.0.3        b
  +    +    +    -    +    +   bbnccf               8.0.0.4

Page 3

RFC 876

Claim Arpa ISI- VRFY RCPT Bad
SMTP  net  Net  Post Post jqkx Host name            Address      Notes
----- ---- ---- ---- ---- ---- ---------            -------      -----
  +    +    +    -    +    +   bbnccp               8.2.0.4
  +    +    +    -    +    +   bbncci               8.3.0.4
  +    +    +    -    +    +   bbnh                 8.4.0.4
  +    -    -    -    -    -   bbn-cdnoc            8.0.0.5
  +    +    +    -    +    +   bbn-cd               8.1.0.5
  +    +    +    -    +    +   bbn-admin            8.1.0.6
  +    +    +    -    +    +   bbn-inoc             8.2.0.6
  +    +    +    -    +    +   bbnccw               8.3.0.6
  +    +    +    -    +    +   bbnccs               8.0.0.7
  +    +    +    -    +    +   bbnz                 8.1.0.7
  +    +    +    -    +    +   bbnccq               8.2.0.7
  +    +    +    -    +    +   bbnccx               8.0.0.8
  +    +    +    -    +    +   bbnccy               8.2.0.8
  +    +    +    -    +    +   csnet-cic            8.0.0.14
  +    +    +    -    +    +   bbn-noc              8.1.0.14
  +    +    +    -    +    -   ucla-cs              10.0.0.1
  -    -    -    -    -    -   ucla-ccn             10.1.0.1
  +    +    +    -    +    -   ucla-locus           10.2.0.1
  +    +    +    -    +    -   ucla-ats             10.3.0.1
  -    -    -    -    -    -   sri-nsc11            10.0.0.2
  +    +    +    +    +    +   sri-kl               10.1.0.2
  +    +    +    -    +    -   sri-csl              10.2.0.2
  +    +    -    -    +    +   sri-tsc              10.3.0.2
  +    +    +    -    +    -   nosc-cc              10.0.0.3
  -    -    -    -    -    -   logicon              10.2.0.3
  +    +    +    -    +    -   nprdc                10.3.0.3
  +    +    +    +    +    +   utah-cs              10.0.0.4
  +    +    +    -    +    -   utah-20              10.3.0.4
  +    +    +    -    +    -   bbnf                 10.0.0.5
  +    +    +    -    +    -   bbng                 10.1.0.5
  +    +    +    -    +    -   bbna                 10.3.0.5
  +    +    +    +    +    +   mit-multics          10.0.0.6
  +    +    +    -    +    -   mit-dms              10.1.0.6
  -    -    -    -    -    -   mit-ai-reserved      10.2.0.6
  +    +    +    -    +    -   mit-ml               10.3.0.6
  +    +    +    +    +    -   rand-relay           10.1.0.7
  +    +    +    -    +    +   rand-unix            10.3.0.7
  +    +    +    -    +    +   nrl                  10.0.0.8
  +    +    +    -    +    -   nrl-aic              10.1.0.8
  +    +    +    -    +    +   nswc-wo              10.2.0.8
  -    -    -    -    -    -   nrl-tops10           10.3.0.8
  -    -    -    -    -    -   nrl-arctan           10.6.0.8
  +    +    +    -    +    -   nrl-css              10.7.0.8
  -    -    -    -    -    -   harv-10              10.0.0.9
  +    +    +    -    +    -   yale                 10.2.0.9
  +    +    +    -    +    +   ll                   10.0.0.10
  +    +    +    -    +    -   ll-vlsi              10.1.0.10
  +    +    -    -    -    +   ll-xn                10.2.0.10
  +    +    -    -    -    +   ll-en                10.4.0.10
  +    -    -    -    -    -   ll-sst               10.6.0.10

Page 4

RFC 876

Claim Arpa ISI- VRFY RCPT Bad
SMTP  net  Net  Post Post jqkx Host name            Address      Notes
----- ---- ---- ---- ---- ---- ---------            -------      -----
  +    +    +    -    +    +   su-ai                10.0.0.11
  +    +    +    +    +    +   su-score             10.3.0.11
  +    +    +    -    +    +   compion-vms          10.0.0.12
  +    +    +    +    +    +   gunter-adam          10.1.0.13
  -    +    +    -    +    -   cmu-cs-b             10.0.0.14
  +    +    +    -    +    -   cmu-cs-a             10.1.0.14
  +    +    +    -    +    -   cmu-cs-c             10.3.0.14
  +    +    +    +    +    -   rochester            10.0.0.15
  +    +    +    -    +    +   ames-tss             10.0.0.16
  +    +    +    -    -    +   ames-vmsa            10.2.0.16
  -    +    +    -    -    +   ames-vmsb            10.3.0.16
  +    +    +    -    +    +   mitre                10.0.0.17
  -    +    +    -    -    +   mitre-gateway        10.1.0.17
  -    -    -    -    -    -   mitre-lan            10.4.0.17
  +    +    +    +    +    +   radc-multics         10.0.0.18
  +    +    +    +    +    +   radc-tops20          10.3.0.18
  -    -    -    -    -    -   radc-unix            10.5.0.18
  +    -    -    -    -    -   ge-crd               10.6.0.18
  +    +    +    -    -    +   nbs-vms              10.0.0.19
  +    +    -    -    -    +   nbs-sdc              10.1.0.19
  -    -    -    -    -    -   nbs-unix             10.2.0.19
  -    -    -    -    -    -   nbs-pl               10.3.0.19
  -    -    -    -    -    -   cctc                 10.0.0.20
  +    +    +    -    +    +   edn-unix             10.3.0.20
  -    +    +    -    -    +   dca-ems              10.4.0.20
  -    -    -    -    -    -   dcec-psat            10.5.0.20
  -    -    -    -    -    -   dcec-itel            10.6.0.20
  -    -    -    -    -    -   dcec-bridge          10.7.0.20
  +    -    -    -    -    -   lll-tis              10.0.0.21
  +    +    +    -    +    -   lll-mfe              10.1.0.21
  -    -    -    -    -    -   lll-zdivision        10.2.0.21
  -    -    -    -    -    -   isi-speech11         10.0.0.22
  +    +    +    +    +    +   usc-isi              10.1.0.22
  +    +    +    +    +    +   usc-isic             10.2.0.22
  +    +    +    -    +    -   usc-eclb             10.0.0.23
  +    +    +    -    +    -   usc-eclc             10.1.0.23
  +    +    +    -    +    -   usc-ecl              10.3.0.23
  +    +    +    -    +    +   nadc                 10.0.0.24
  -    -    -    -    -    -   wharton-10           10.3.0.24
  +    +    +    +    +    +   seismo               10.0.0.25
  +    +    +    +    +    +   usc-isid             10.0.0.27
  -    -    -    -    -    -   isi-png11            10.1.0.27
  +    +    +    -    +    -   isi-vaxa             10.2.0.27
  -    -    -    -    -    -   isi-mcon             10.1.21.27
  -    -    -    -    -    -   isi-wbc11            10.1.23.27
  -    -    -    -    -    -   isi-maint11          10.1.25.27
  -    -    -    -    -    -   isi-setting          10.1.89.27
  -    -    -    -    -    -   isi-loretta          10.1.90.27
  -    -    -    -    -    -   isi-pallas-athene    10.1.91.27
  -    -    -    -    -    -   isi-aikane           10.1.97.27

Page 5

RFC 876

Claim Arpa ISI- VRFY RCPT Bad
SMTP  net  Net  Post Post jqkx Host name            Address      Notes
----- ---- ---- ---- ---- ---- ---------            -------      -----
  -    -    -    -    -    -   isi-czar             10.1.98.27
  -    -    -    -    -    -   isi-mycroftxxx       10.1.99.27
  -    -    -    -    -    -   isi-cmr              10.1.124.27
  -    -    -    -    -    -   isi-ihm              10.1.125.27
  -    +    -    -    -    +   arpa-dms             10.0.0.28
  +    -    -    -    -    -   arpa-png11           10.3.0.28
  +    +    +    -    +    +   brl                  10.0.0.29
  +    +    +    -    -    +   apg-1                10.1.0.29
  +    +    -    -    +    -   cca-unix             10.0.0.31
  +    +    +    -    -    +   cca-vms              10.1.0.31
  +    +    +    -    +    -   parc-maxc            10.0.0.32
  +    +    -    -    +    -   kestrel              10.3.0.32
  -    -    -    -    -    -   nps                  10.0.0.33
  -    -    -    -    -    -   fnoc-secure          10.3.0.33
  +    +    +    -    -    +   lbl-nmm              10.0.0.34
  +    +    -    +    +    +   lbl-csam             10.1.0.34
  -    -    -    -    -    -   nosc-secure2         10.0.0.35
  +    +    -    -    -    +   nosc-tecr            10.1.0.35
  -    -    -    -    -    -   nosc-secure3         10.3.0.35
  -    -    -    -    -    -   nosc-f4              10.4.0.35
  -    -    -    -    -    -   coins-tas            10.0.0.36
  -    -    -    -    -    -   cincpacflt-wm        10.1.0.36
  +    +    +    -    +    -   purdue               10.0.0.37
  +    -    -    -    -    -   bragg-sta1           10.1.0.38
  -    -    -    -    -    -   bbn-psat-ig          10.2.0.40
  +    +    +    -    +    +   office-1             10.0.0.43
  +    +    +    -    +    +   office-2             10.1.0.43
  +    +    -    -    +    +   office-3             10.2.0.43
  +    +    -    -    +    +   office-7             10.3.0.43
  +    +    +    -    +    -   mit-xx               10.0.0.44
  -    -    -    -    -    -   mit-tstgw            10.2.0.44
  +    +    +    -    +    -   mit-mc               10.3.0.44
  +    +    -    -    +    +   ardc                 10.1.0.45
  -    -    -    -    -    -   collins-pr           10.0.0.46
  -    -    -    -    -    -   collins-gw           10.1.0.46
  -    -    -    -    -    -   okc-unix             10.3.0.46
  -    -    -    -    -    -   wpafb                10.0.0.47
  +    -    -    -    -    -   wpafb-afwal          10.1.0.47
  -    -    -    -    -    -   afwl                 10.1.0.48
  +    +    +    -    +    -   bbnb                 10.0.0.49
  +    +    +    -    +    -   bbnc                 10.3.0.49
  +    +    +    -    +    +   bbn-clxx             10.4.0.49
  +    +    +    +    +    +   st-nic               10.0.0.51
  -    -    -    -    -    -   sri-sta6             10.1.1.51
  +    +    -    +    +    +   srijoyce             10.1.4.51
  +    +    -    -    +    +   sri-unix             10.2.0.51
  -    -    -    -    -    -   sri-sta2             10.3.1.51
  -    -    -    -    -    -   sri-prmh             10.3.2.51
  +    +    +    -    +    +   ada-vax              10.0.0.52
  +    +    +    +    +    +   usc-isie             10.1.0.52

Page 6

RFC 876

Claim Arpa ISI- VRFY RCPT Bad
SMTP  net  Net  Post Post jqkx Host name            Address      Notes
----- ---- ---- ---- ---- ---- ---------            -------      -----
  +    +    +    +    +    +   usc-isif             10.2.0.52
  +    +    +    +    +    +   usc-isib             10.3.0.52
  -    -    -    -    -    -   afsc-ad              10.0.0.53
  -    -    -    -    -    -   afsc-dev             10.2.0.53
  -    -    -    -    -    -   ncsc                 10.4.0.53
  -    -    -    -    -    -   martin               10.5.0.53
  +    +    +    +    +    +   cit-20               10.0.0.54
  +    +    +    -    +    -   cit-vax              10.1.0.54
  -    +    -    -    -    +   acc                  10.2.0.54
  +    +    +    -    -    +   jpl-vax              10.3.0.54
  +    +    -    -    -    +   anl-mcs              10.1.0.55      a
  +    +    +    +    +    +   sumex-aim            10.0.0.56
  +    +    +    -    +    +   su-dsn               10.1.0.56
  +    +    +    -    +    +   aids-unix            10.2.0.56
  -    -    -    -    -    -   tycho                10.0.0.57
  -    -    -    -    -    -   coins-gateway        10.1.0.57
  +    +    +    -    +    -   nyu                  10.0.0.58
  +    +    +    -    +    +   bnl                  10.1.0.58
  +    +    +    +    +    +   rutgers              10.2.0.58
  +    +    +    +    +    -   ru-green             10.2.1.58
  +    +    +    +    +    -   ru-blue              10.2.2.58
  +    +    +    +    +    +   stl-host1            10.0.0.61
  +    -    -    -    -    -   almsa-1              10.1.0.61
  +    +    -    +    +    +   utexas-11            10.0.0.62
  +    +    +    +    +    +   utexas-20            10.1.0.62
  -    +    -    +    +    +   utexas-780           10.2.0.62
  +    +    -    -    -    +   martin-b             10.1.0.64
  -    -    -    -    -    -   robins-unix          10.3.0.64
  -    -    -    -    -    -   afsc-sd              10.0.0.65
  +    +    +    -    +    -   aerospace            10.2.0.65
  -    -    -    -    -    -   afgl                 10.1.0.66
  +    +    +    -    +    -   mitre-bedford        10.3.0.66
  -    +    +    +    +    +   afsc-hq              10.0.0.67
  +    +    +    +    +    +   usgs1-multics        10.0.0.68
  -    -    -    -    -    -   usgs1-amdahl         10.2.0.68
  +    +    +    +    +    +   usgs2-multics        10.0.0.69
  +    +    -    +    +    -   usgs3-multics        10.0.0.70      b
  +    -    -    -    -    -   usgs3-vms            10.2.0.70
  -    -    -    -    -    -   bbn-tmp2             10.2.0.71
  +    +    +    -    +    +   bbn-unix             10.1.0.72
  +    +    +    -    +    -   sri-nic              10.0.0.73
  -    -    -    -    -    -   sri-warf             10.1.0.73
  +    +    +    +    +    +   sri-ai               10.2.0.73
  +    +    -    -    -    +   sri-iu               10.3.0.73
  -    +    -    -    -    +   sri-vax              10.3.2.73
  +    -    -    -    -    -   sri-spam-test        10.4.0.73
  +    -    -    -    -    -   simtel20             10.0.0.74
  +    +    +    -    -    +   wsmr70a              10.1.0.74
  +    +    +    -    -    +   wsmr70b              10.3.0.74
  -    +    +    -    -    +   yuma                 10.3.0.75

Page 7

RFC 876

Claim Arpa ISI- VRFY RCPT Bad
SMTP  net  Net  Post Post jqkx Host name            Address      Notes
----- ---- ---- ---- ---- ---- ---------            -------      -----
  +    -    -    -    -    -   obl-em               10.0.0.76
  +    +    +    +    +    +   cisl-service-multics 10.1.0.77
  +    -    -    -    -    -   mit-oz               10.3.0.77
  +    +    +    +    +    +   ucb-arpa             10.0.0.78
  +    +    +    +    +    +   ucb-vax              10.2.0.78
  -    -    -    -    -    -   mcclellan            10.3.0.78
  +    +    +    +    +    +   dec-tops20           10.0.0.79
  +    +    +    +    +    +   dec-marlboro         10.1.0.79
  +    +    +    +    +    +   hi-multics           10.0.0.80
  +    +    +    -    +    +   nems                 10.0.0.81
  +    +    +    -    +    +   nalcon               10.1.0.81
  +    +    +    -    +    +   nsrdcoa              10.3.0.81
  +    +    +    -    +    +   bbncct               10.0.0.82
  +    +    +    +    +    +   bbn-vax              10.1.0.82
  +    +    +    -    +    +   ddn1                 10.3.0.82
  -    -    -    -    -    -   bbn-rsm              10.4.0.82
  +    +    +    -    +    +   bbn-noc2             10.6.0.82
  -    -    -    -    -    -   test-mailbr          10.7.0.82
  -    +    +    -    +    +   minet-lon            10.0.0.83
  -    +    +    -    +    -   minet-noc            10.1.0.83      b
  +    +    -    -    +    -   tac-news             10.2.0.83      b
  -    -    -    -    -    -   test-bridge          10.3.0.83
  -    -    -    -    -    -   nswc-dl              10.0.0.84
  -    +    -    -    +    -   nswc-g               10.1.0.84
  +    +    -    -    -    +   nwc-387a             10.0.0.85
  +    +    +    -    +    +   nwc-387b             10.3.0.85
  +    +    +    -    +    +   stt-noc              10.0.0.86
  +    +    +    +    +    +   sandia               10.0.0.87
  +    +    +    +    +    +   nlm-mcs              10.0.0.88
  +    +    +    +    +    +   columbia-20          10.0.0.89
  +    +    +    -    +    -   lanl                 10.0.0.90
  +    +    +    +    +    +   washington           10.0.0.91
  +    +    +    -    +    -   uw-vlsi              10.3.0.91
  -    -    -    -    -    -   nusc-npt             10.2.0.92
  -    +    -    -    -    +   nusc                 10.3.0.92
  +    +    -    -    +    +   office-8             10.0.0.93
  +    +    +    -    +    +   office-10            10.1.0.93
  +    +    +    -    +    +   office-15            10.2.0.93
  +    +    +    -    +    -   uwisc                10.1.0.94
  -    -    -    -    -    -   s1-gateway           10.0.0.95
  +    +    +    -    -    +   s1-a                 10.1.0.95
  +    -    -    -    -    -   s1-b                 10.2.0.95
  +    +    +    -    +    -   s1-c                 10.3.0.95
  +    +    +    +    +    -   udel-relay           10.0.0.96
  -    -    -    -    -    -   udel-tcp             10.1.0.96
  +    +    -    -    +    +   udel-ee              10.2.0.96
  +    +    -    +    +    +   cornell              10.3.0.96
  +    +    +    -    -    +   paxrv-nes            10.2.0.97
  -    -    -    -    -    -   uwisc-x25            10.3.0.99
  +    -    -    -    -    -   purdue-tn            14.0.0.1

Page 8

RFC 876

Claim Arpa ISI- VRFY RCPT Bad
SMTP  net  Net  Post Post jqkx Host name            Address      Notes
----- ---- ---- ---- ---- ---- ---------            -------      -----
  +    -    -    -    -    -   uwisc-tn             14.0.0.2
  +    -    -    -    -    -   udel-tn              14.0.0.3
  -    -    -    -    -    -   ucl-vtest            14.0.0.4
  -    -    -    -    -    -   uk-satnet            14.0.0.6
  -    -    -    -    -    -   wisc-ibm             14.0.0.7
  +    -    -    -    -    -   rand-tn              14.0.0.8
  -    -    -    -    -    -   mit-br-ethernet      18.2.0.7
  -    -    -    -    -    -   mit-tiu              18.2.0.15
  -    -    -    -    -    -   mit-alto-509         18.2.0.18
  -    -    -    -    -    -   mit-alto-510         18.2.0.20
  -    -    -    -    -    -   mit-alto-524         18.2.0.32
  -    -    -    -    -    -   mit-alto-214b        18.2.0.56
  -    -    -    -    -    -   mit-alto-511         18.2.0.72
  -    -    -    -    -    -   mit-muriel           18.2.0.80
  -    -    -    -    -    -   mit-alto-508         18.2.0.96
  -    -    -    -    -    -   mit-alto-503         18.2.0.100
  -    -    -    -    -    -   mit-spooler          18.2.0.128
  -    -    -    -    -    -   mit-np-alto          18.2.0.129
  -    -    -    -    -    -   mit-alto-502         18.2.0.130
  -    -    -    -    -    -   mit-alto-828         18.2.0.134
  -    -    -    -    -    -   mit-alto-520         18.2.0.170
  -    -    -    -    -    -   mit-gw-lcs           18.8.0.4
  -    -    -    -    -    -   mit-bridge           18.8.0.5
  -    -    -    -    -    -   mit-rts              18.8.0.9
  -    -    -    -    -    -   mit-rts40            18.8.0.10
  -    -    -    -    -    -   mit-vax              18.8.0.16
  -    -    -    -    -    -   mit-xx-11            18.8.0.32
  +    +    +    -    +    -   mit-csr              18.10.0.8
  -    -    -    -    -    -   mit-rts40-v2         18.10.0.10
  -    +    +    -    +    -   mit-ajax             18.10.0.64
  -    +    +    -    +    -   mit-borax            18.10.0.65
  -    +    +    -    +    -   mit-comet            18.10.0.66
  -    -    -    -    -    -   mit-dutch            18.10.0.67
  -    +    +    -    +    -   mit-mrclean          18.10.0.68
  -    +    +    -    +    -   mit-bold             18.10.0.69
  -    +    +    -    +    -   mit-fab              18.10.0.70
  -    +    +    -    +    -   mit-prj              18.10.0.71
  -    +    +    -    +    -   mit-duz              18.10.0.72
  -    +    +    -    +    -   mit-dash             18.10.0.73
  -    +    +    -    +    -   mit-tide             18.10.0.74
  -    +    -    -    +    -   mit-fla              18.10.0.75
  +    +    +    -    +    -   mit-cls              18.10.0.76
  -    +    +    -    +    -   mit-grape-nehi       18.10.0.77
  -    +    +    -    +    -   mit-heineken         18.10.0.78
  -    +    +    -    +    -   mit-oa               18.10.0.79
  -    -    -    -    -    -   mit-macewan          18.10.0.80
  -    -    -    -    -    -   mit-kirin            18.10.0.81
  -    +    +    -    +    -   mit-molson           18.10.0.82
  -    +    +    -    +    -   mit-milo             18.10.0.86
  -    +    +    +    +    +   mit-opus             18.10.0.87

Page 9

RFC 876

Claim Arpa ISI- VRFY RCPT Bad
SMTP  net  Net  Post Post jqkx Host name            Address      Notes
----- ---- ---- ---- ---- ---- ---------            -------      -----
  -    +    +    -    +    -   mit-rinso            18.10.0.88
  -    -    -    -    -    -   rsre                 25.8.0.0
  +    +    +    -    +    -   su-shasta            36.40.0.192
  +    +    +    +    +    +   su-hnv               36.40.0.193
  +    +    +    +    +    +   su-navajo            36.40.0.203
  +    +    +    +    +    +   su-whitney           36.40.0.204
  +    +    +    -    +    +   su-glacier           36.40.0.205
  +    +    -    -    -    +   su-star              36.40.0.207
  +    +    +    +    +    -   su-carmel            36.40.0.212
  +    +    +    +    +    +   su-sierra            36.40.0.213
  +    -    -    -    -    -   su-ardvax            36.45.0.85
  +    -    -    -    -    -   su-safe              36.45.0.86
  +    +    -    -    +    +   sri-tsca             39.128.3.59
  -    -    -    -    -    -   sri-rolm             45.0.32.4
  -    +    -    +    +    +   ucbarpa              46.0.0.4
  -    +    -    +    +    +   ucbcad               46.0.0.5
  -    +    -    +    -    +   ucbernie             46.0.0.6
  -    +    -    +    +    +   ucbmonet             46.0.0.7
  -    +    -    +    -    +   ucbesvax             46.0.0.9
  +    +    -    +    +    +   ucbvax               46.0.0.10
  -    +    -    +    +    +   ucbkim               46.0.0.11
  -    +    -    +    +    +   ucbcalder            46.0.0.12
  -    +    -    +    -    +   ucbdali              46.0.0.13
  -    +    -    +    -    +   ucbmatisse           46.0.0.14
  -    +    -    +    -    +   ucbmedea             46.0.0.15
  -    +    -    +    +    +   ucbingres            46.0.0.19
  +    +    -    +    +    +   sac-vax              47.0.32.3
  +    +    -    -    +    -   ndre1                48.3.1.41
  -    +    -    +    -    +   nta-vax              50.0.0.8
  +    +    -    -    +    -   cmu-cs-ius           128.2.254.128
  +    +    -    -    +    -   cmu-cs-vlsi          128.2.254.129
  -    -    -    -    -    -   cmu-cs-ps1           128.2.254.130
  +    +    -    -    +    -   cmu-cs-zog           128.2.254.131
  +    +    -    -    +    -   cmu-cs-g             128.2.254.132
  +    +    -    -    +    -   cmu-cs-cad           128.2.254.133
  +    -    -    -    -    -   cmu-cs-k             128.2.254.136
  +    +    -    -    +    -   cmu-ri-fas           128.2.254.138
  +    +    -    -    +    -   cmu-cs-spice         128.2.254.139
  +    +    -    -    +    -   cmu-cs-gandalf       128.2.254.140
  +    -    -    -    -    -   cmu-ri-leg           128.2.254.141
  +    +    -    -    +    -   cmu-ri-isl1          128.2.254.143
  -    -    -    -    -    -   cmu-cs-j             128.2.254.144
  +    +    -    -    +    -   cmu-cs-speech        128.2.254.145
  -    -    -    -    -    -   cmu-cs-ps2           128.2.254.146
  +    +    -    -    +    -   cmu-cs-unh           128.2.254.150
  +    +    -    -    +    -   cmu-ri-arm           128.2.254.151
  +    +    -    -    +    -   cmu-ri-isl2          128.2.254.152
  +    +    -    -    +    -   cmu-cs-cfs           128.2.254.153
  +    +    -    -    +    -   cmu-cs-jk            128.2.254.154
  +    +    -    -    +    -   cmu-cs-pt            128.2.254.155

Page 10

RFC 876

Claim Arpa ISI- VRFY RCPT Bad
SMTP  net  Net  Post Post jqkx Host name            Address      Notes
----- ---- ---- ---- ---- ---- ---------            -------      -----
  +    +    -    -    +    -   cmu-cs-h             128.2.254.156
  +    +    -    -    +    -   cmu-ri-rover         128.2.254.157
  +    +    -    -    +    -   dcn1                 128.4.0.1
  +    -    -    -    -    -   dcn2                 128.4.0.2
  +    +    -    -    +    -   dcn3                 128.4.0.3
  +    -    -    -    -    -   dcn4                 128.4.0.4
  +    +    -    -    +    -   dcn5                 128.4.0.5
  +    +    -    -    +    -   dcn6                 128.4.0.6
  +    +    -    -    +    -   dcn7                 128.4.0.7
  +    +    -    -    +    -   dcn8                 128.4.0.8      b
  +    -    -    -    -    -   dcn9                 128.4.0.9
  +    +    -    -    +    -   ford1                128.5.0.1
  +    +    -    -    +    -   ford2                128.5.0.2
  +    +    -    -    +    -   ford3                128.5.0.3
  +    +    -    -    +    -   ford4                128.5.0.4
  +    +    -    -    +    -   ford-lab             128.5.0.8
  +    -    -    -    -    -   ford-vax             128.5.0.9
  +    -    -    -    -    -   ford-res             128.5.0.10
  +    +    -    -    +    -   ford-ecc             128.5.0.11
  +    +    -    -    +    -   ford-srl             128.5.0.12
  +    +    -    -    +    -   ford-ers             128.5.0.13
  +    +    -    -    +    -   ford-eed             128.5.0.14     b
  +    +    -    -    +    -   ford-foe             128.5.0.15     b
  +    +    -    -    -    +   ford-wdl1            128.5.32.1
  +    -    -    -    -    -   ford-wdl2            128.5.32.2
  +    +    -    -    +    -   ford-wdl3            128.5.32.3
  +    -    -    -    -    -   ford-wdl4            128.5.32.4
  +    +    -    -    -    +   ford-wdl5            128.5.32.5
  -    +    -    -    -    +   ford-wdl6            128.5.32.6
  +    -    -    -    -    -   dfvlr1               128.7.0.1
  +    -    -    -    -    -   dfvlr2               128.7.0.2
  +    -    -    -    -    -   dfvlr3               128.7.0.3
  +    -    -    -    -    -   dfvlr7               128.7.0.7
  +    +    -    -    +    -   umd1                 128.8.0.1
  +    +    -    -    +    -   umd2                 128.8.0.2
  +    +    -    -    +    -   umd3                 128.8.0.3
  +    +    -    -    +    -   cvl                  128.8.0.4
  +    +    -    -    +    -   umd5                 128.8.0.5
  +    -    -    -    -    -   umd6                 128.8.0.6
  +    -    -    -    -    -   umd7                 128.8.0.7
  +    +    -    -    +    -   umd-csd              128.8.0.8
  +    -    -    -    -    -   umd9                 128.8.0.9
  +    -    -    -    -    -   umda                 128.8.0.10
  +    -    -    -    -    -   umdb                 128.8.0.11
  +    -    -    -    -    -   umdc                 128.8.0.12
  +    -    -    -    -    -   umdd                 128.8.0.13
  +    -    -    -    -    -   umde                 128.8.0.14
  +    -    -    -    -    -   umdf                 128.8.0.15
  -    -    -    -    -    -   isi-accutest         128.9.0.24
  -    -    -    -    -    -   isi-elvira           128.9.0.41

Page 11

RFC 876

Claim Arpa ISI- VRFY RCPT Bad
SMTP  net  Net  Post Post jqkx Host name            Address      Notes
----- ---- ---- ---- ---- ---- ---------            -------      -----
  -    -    -    -    -    -   isi-hobgoblin        128.9.0.42
  -    -    -    -    -    -   isi-moe              128.9.0.43
  -    -    -    -    -    -   isi-troll            128.9.0.44
  -    -    -    -    -    -   isi-curly            128.9.0.45
  -    -    -    -    -    -   isi-shemp            128.9.0.46
  -    -    -    -    -    -   isi-zombie           128.9.0.47
  -    -    -    -    -    -   isi-xorn             128.9.0.48
  -    +    -    -    -    +   isi-vlsia            128.9.0.49
  -    +    +    -    -    +   isi-vlsib            128.9.0.50
  -    -    -    -    -    -   isi-dawn             128.9.0.92
  -    -    -    -    -    -   isi-rising           128.9.0.93
  -    -    -    -    -    -   isi-spanky           128.9.0.112
  -    -    -    -    -    -   isi-alfalfa          128.9.0.113
  -    -    -    -    -    -   isi-darla            128.9.0.114
  -    -    -    -    -    -   isi-buckwheat        128.9.0.115
  -    -    -    -    -    -   isi-stymie           128.9.0.116
  -    -    -    -    -    -   isi-farina           128.9.0.117
  -    -    -    -    -    -   isi-pete             128.9.0.118
  -    -    -    -    -    -   isi-froggie          128.9.0.119
  -    -    -    -    -    -   isi-wab2             128.9.0.121
  -    -    -    -    -    -   isi-randy            128.9.0.122
  -    -    -    -    -    -   isi-rag2             128.9.0.123
  +    +    -    -    +    -   csnet-purdue         128.10.0.2
  +    +    -    -    -    +   bbn-cvax             128.11.0.2
  +    +    -    -    -    +   bbnv1                128.11.64.1
  -    -    -    -    -    -   ucl-lsih             128.16.1.67
  -    -    -    -    -    -   ucl-lsil             128.16.1.106
  -    -    -    -    -    -   ucl-lsim             128.16.1.110
  -    -    -    -    -    -   ucl-lsii             128.16.1.112
  -    -    -    -    -    -   ucl-lsij             128.16.1.113
  -    -    -    -    -    -   ucl-lsik             128.16.1.115
  -    -    -    -    -    -   ucl-terminal-gateway 128.16.3.2
  -    -    -    -    -    -   ucl-sam              128.16.9.0
  -    -    -    -    -    -   ucl-probe            128.16.9.1
  -    +    -    -    +    +   ucl-tg               128.16.9.2
  +    -    -    -    -    -   ucl-cs               128.16.9.3
  -    -    -    -    -    -   ucl-niftp            128.16.9.4
  +    -    -    -    -    -   edn-host1            128.19.1.1
  +    -    -    -    -    -   brl-hep              128.20.1.2
  +    +    -    -    +    +   amsaa                128.20.3.1
  +    +    -    -    +    +   brl-voc              128.20.3.2
  +    +    -    -    +    +   hel-ace              128.20.3.4
  +    +    -    +    +    +   sri-spam             128.21.32.2
  -    +    -    -    +    -   wisc-rsch            192.5.2.1
  -    +    -    -    +    -   wisc-db              192.5.2.2
  -    +    -    -    +    -   wisc-crys            192.5.2.7
  +    +    -    -    -    +   cit-750              192.5.7.3
  +    +    -    -    +    -   uw-beaver            192.5.8.1
  +    +    -    -    +    -   uw-lumpy             192.5.8.2      b
  +    +    -    -    +    -   uw-wally             192.5.8.3

Page 12

RFC 876

Claim Arpa ISI- VRFY RCPT Bad
SMTP  net  Net  Post Post jqkx Host name            Address      Notes
----- ---- ---- ---- ---- ---- ---------            -------      -----
  +    +    -    -    +    -   uw-june              192.5.8.4
  +    +    -    -    +    -   uw-eddie             192.5.8.6
  +    +    -    +    +    +   utah-gr              192.5.12.22
  +    +    -    +    +    +   utah-sp              192.5.12.23
  +    -    -    -    -    -   nyu-cmcl1            192.5.15.5
  +    -    -    -    -    -   nyu-acf2             192.5.15.9
  +    +    -    -    +    +   brl-bmd              192.5.21.1
  +    +    -    -    +    +   brl-vld              192.5.21.2
  -    -    -    -    -    -   brl-svg              192.5.21.3
  +    -    -    -    -    -   brl-tgr              192.5.21.4
  +    +    -    -    +    +   brl-vgr              192.5.21.6
  +    -    -    -    -    -   cornell-pvax         192.5.36.4

Notes
-----
 a) "VRFY postmaster" gave an unknown user reply; all other negative
    replies were because VRFY was not implemented.

 b) No connection could be opened to this host during the test of
    mailing to nonexistent users

Page 13