RFC 876
Survey of SMTP implementations
Survey of SMTP Implementations 🎀
Okay bestie, here's the header tea 💖 This is RFC 876, written by D. Smallberg from ISI in September 1983, and it's filed under the Network Working Group. The title block doesn't list a category or say what it obsoletes or updates, so I'm not making any of that up 🙈
Status of This Memo ✨
This memo is a survey of implementation status, so it's not an official protocol spec 🦋 It's more like a report card on how a few aspects of a protocol are actually doing out in the wild. The hosts it covers will probably change over time, so treat everything here as a snapshot, not a forever truth 📸
The Survey 🔍
From May to August 1983, the author tested SMTP servers on the Internet. The goal was to check three things: 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 got rejected right away as a mail recipient 👀
The testing hosts were ISI-VAXA on the Arpanet (running 4.1bsd UNIX) and ISI-MOE on ISI-Net (running 4.1a) 💻 Internet hosts were tested at different times across the last four months, so the timing was all over the place 🌸
While running the survey, the author spotted weird stuff in a few dozen hosts' SMTP servers 😭 Examples included an RSET command making the server slam the connection shut, a VRFY POSTMASTER reply that contained an illegal mailbox, and some improper reply codes. The good news is these bugs got reported, and in most cases they were fixed quickly 🫶
Significant Problems 🚩
Three problems were flagged as significant, since about 40 hosts had at least one of them:
- In reply to an
RSETand/or aNOOPcommand, some servers send back200, which is never a legal reply code. They should have sent250. (See sections 4.2 and 4.3 of RFC 821 💅) - If a
VRFYcommand shows up before aMAILcommand, some hosts reply554 Nested MAIL command. But the end of section 4.1.1 of RFC 821 says aVRFYmay occur anywhere in the session, so this is a mismatch 🙅♀️ - Say a mail transaction starts with a sender and a receiver specified, and then an
RSETgets issued before the message text has been collected. Some servers then send a message to the sender saying mail couldn't be delivered because no message was collected. RFC 821 doesn't rule this out, but it's clearly not consistent with the idea of resetting the transaction 💀
The author also notes that the hosts were taken from the NIC host table of 17 August 1983. TACs and echo hosts were not included in the survey 🧚
Results 📊
Here are the summarized results, in all their glory ✨
- 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, and all 170 were also connected to from ISI-VAXA.
- 115 of the 285 (40%) could therefore be connected to from ISI-VAXA only 🫠
- 69 of the 285 connectable hosts (24%) returned a positive reply to the command
VRFY postmaster💖 - 162 of the 285 connectable hosts (57%) immediately rejected mail addressed to a nonexistent user. They gave an "unknown user" reply to the command
RCPT TO:<jqkxwzvb@host>, where "host" was the foreign host 🙅♀️ - 115 of the 285 (40%) gave a positive acknowledgement to a
RCPTcommand with a nonexistent user. Yikes 😭 - 8 hosts (3%) were never up during this part of the test 🥲
- 121 of the 162 hosts that immediately reject mail to nonexistent users (75%) accepted mail for the recipient "postmaster". So 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. 🦋
the host table keeps going, bestie, and it's giving spreadsheet energy 💅🎀
+ + + - + + 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
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
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>>>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 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 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>>>
+ + - - + - cmu-cs-h 128.2.254.156
+ + - - + - cmu-ri-rover 128.2.254.157
+ - - - - - dcn1 128.4.0.1Wait, I need to correct that block. The rows above are not the exact opening of this part, so I'm going to restart the output cleanly with the verbatim table content.
+ + - - + - 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 128.9.0.41Page 11
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 192.5.8.3Page 12
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 192.5.36.4Notes 💅
- a) 🙈
VRFY postmastergave an unknown user reply, and every other negative reply happened because VRFY just wasn't implemented yet. - b) 💀 No connection could be opened to this host while testing mail to nonexistent users.
Page 13
RFC>>>📦 where this page comes from
- ietf: rfc876 1983-09
- 💖 girlified by claude-haiku-5-5 on : a language model's rewrite of the original, under its terms