Testing email - various ways

Testing IMAP via telnet
Testing SMTP via telnet
Testing POP3 via telnet

The links above provide much more detail than my "cheat sheet."

MAIL Server testing

SMTP

[localhost:~] matt% telnet mail.example.com smtp
Trying 64.224.19.12...
Connected to mail.example.com.
Escape character is '^ ]'.
220 mail.example.com ESMTP
ehlo
250-mail.example.com
250-AUTH LOGIN PLAIN
250-AUTH=LOGIN PLAIN
250-PIPELINING
250-STARTTLS
250 8BITMIME
mail from:me@mydomain.com
250 ok
rcpt to:you@example.com
250 ok
data
354 go ahead
To:Your Name<you@example.com>
From: My Name<me@mydomain.com>
Subject: email test

This is the message body. It ends with a single . on a blank line.
.
250 ok 1016471746 qp 9246

While this still works, I don't use it very often. Not since I discovered swaks.

POP3

telnet pop.domain.com pop3
+OK Hello there.
user user@example.net
+OK Password required.
pass secret
+OK
list
1 1586
2 13304
3 795
.
dele 2
+OK
quit
Connection closed by foreign host.

IMAP

telnet imap.example.com imap
Escape character is '^ ]'.
* OK Courier-IMAP ready. Copyright 1998-2002 Double Precision, Inc. See COPYING for distribution information.
. login user@example.com secret
. OK LOGIN Ok.
A0001 CAPABILITY
* CAPABILITY IMAP4rev1 CHILDREN NAMESPACE THREAD=ORDEREDSUBJECT THREAD=REFERENCES SORT QUOTA
. logout
* BYE Courier-IMAP server shutting down
. OK LOGOUT completed