
点検時にいつも、ネット検索して利用していたのでメモする
メールサーバーに接続する
$ telnet 172.26.XXX.XXX 25 Trying 172.26.XXX.XXX... Connected to 172.26.XXX.XXX. Escape character is '^]'. 220 mail.dokoka.net ESMTP Postfix
メールサーバーに挨拶
helo mail.dokoka.net 250 mail.dokoka.net
送信元を記入する
MAIL FROM:dokoka@gmail.com 250 2.1.0 Ok
送信先を記入する
RCPT TO:tatsuo@dokoka.net 250 2.1.5 Ok
本文を記入する
※メーリングリストでは、from: To:が無いと反応しない。(ezmlm)
DATA 354 End data with <CR><LF>.<CR><LF> from:dokoka@gmail.com To:mail@dokoka.co.jp subject:Test Mail aaabbbccc TestMail . 250 2.0.0 Ok: queued as E406740CF7D quit 221 2.0.0 Bye Connection closed by foreign host.
メールが届く、メールソースの内容
Return-Path: <ishi025@gmail.dokoka.net> X-Original-To: tatsuo@dokoka.net Delivered-To: tatsuo@dokoka.net Received: from mail.aitake.net (ip-172-26-XXX-XXX.ap-northeast-1.compute.internal [172.26.XXX.XXX]) by mail.dokoka.net (Postfix) with SMTP id E406740CF7D for <tatsuo@dokoka.net>; Mon, 4 Apr 2022 10:11:43 +0900 (JST) from:dokoka@gmail.com subject:Test Mail aaabbbccc TestMail
pop3でtelnetも
$ telnet localhost 110 Trying 127.0.0.1... Connected to localhost. Escape character is '^]'. +OK Dovecot ready. USER user +OK PASS {password} +OK Logged in.

ついでに、メール受信(POP)も
$ telnet pop.docoka.co,jp 110 Trying 10.10.10.10… Connected to pop.docoka.co.jp Escape character is ‘^]’. +OK <82592.1252945008@host> user your-emailusername +OK pass youremailpassword +OK stat +OK 1 529 list +OK 1 messages: 1 529 . (メール内容参照) retr 1 +OK 529 octets Return-Path: <eigyo@docoka.co.jp> X-Original-To: eigyo@docoka.co.jp Delivered-To: eigyo@docoka.co.jp Received: from docoka.co.jp (ip-10-10-10-10.ap-northeast-1.compute.internal [10.10.10.10]) by docoka.co.jp (Postfix) with SMTP id B664014B286 for <eigyo@docoka.co.jp>; Fri, 12 Apr 2022 04:32:49 +0000 (UTC) from:eigyo@docoka.co.jp to:eigyo@docoka.co.jp subject:Test Mail . (メール削除) dele 1 +OK Marked to be deleted. quit +OK Logging out, messages deleted. Connection closed by foreign host.

GmailのPOP受信をTelnetで行う場合
まだ書いていません♬