1 前言

笔者有时候调试邮件服务器需要使用Telnet直接去操纵IMAP与SMTP的服务，所以整理此文。

2 最佳实践

2.1 IMAP服务

2.1.1 使用Telnet链接IMAP服务

telnet imap.cmdschool.org 143

信息显示如下，

Trying 113.96.209.109...
Connected to imap.cmdschool.org.
Escape character is '^]'.
* OK Domino IMAP4 Server Release 9.0.1FP3 ready Tue, 3 Sep 2019 09:19:36 +0800

2.1.2 登录邮箱

a01 login username password

登录成功你将会看到如下提示，

a01 OK LOGIN completed

2.1.3 列出所有信箱

a02 list "" *

将会看到如下提示，

* LIST (\HasNoChildren) "\\" Drafts
* LIST (\Noinferiors \HasNoChildren) "\\" Inbox
* LIST (\HasNoChildren) "\\" Sent
[...]
a02 OK LIST completed

2.1.4 退出协议

a03 logout

命令显示如下，

* BYE logging out
Connection closed by foreign host.

2.1 SMTP服务

2.1.1 使用Telnet链接SMTP服务

telnet smtp.cmdschool.org 25

信息显示如下，

Trying 113.96.232.106...
Connected to smtp.cmdschool.org.
Escape character is '^]'.
220 smtp.cmdschool.org ESMTP Service (IBM Domino Release 9.0.1FP3) ready at Tue, 3 Sep 2019 09:46:31 +0800

2.1.2 helo指令

helo cmdschool.org

250 smtp.cmdschool.org Hello cmdschool.org ([113.96.232.106]), pleased to meet you

2.1.3 声明发件人

mail from:will@cmdschool.org

信息显示如下，

250 will@cmdschool.org... Sender OK

2.1.4 声明主送人

rcpt to:free@cmdschool.org

信息显示如下，

250 free@cmdschool.org.. Recipient OK

2.1.5 声明邮件正文

data

可见如下提示，

354 Enter message, end with "." on a line by itself

根据向导输入邮件正文与结束符号，

test
.

信息显示如下，

250 Message accepted for delivery

参阅文档
======================

IMAP的文档
—————–
https://blog.csdn.net/pathfinder163/article/details/6397199
https://busylog.net/imap-telnet-example-test-imap-with-telnet/

SMTP的文档
—————
http://www-01.ibm.com/support/docview.wss?uid=swg21568052