Admin Life Errors, Fixes, and Encounters

Send a test mail using Telnet

Telnet into the smtp server (postfix)

# telnet localhost 25

The server should reply with:

Trying 127.0.0.1...
Connected to localhost.
Escape character is '^]'.
220 mytestmail.com ESMTP Postfix

Great. Postfix is listening and wants us to speak SMTP:

ehlo example.com

Postfix appreciates the EHLO and tells us which features it provides:

250-my-new-mailserver
250-PIPELINING
250-SIZE 10240000
250-VRFY
250-ETRN
250-ENHANCEDSTATUSCODES
250-8BITMIME
250 DSN

Hey, Postfix, we have a mail from [email protected]:

mail from:<[email protected]>

Looks like Postfix is happy with that because return codes that start with a '2' are good news:

250 2.1.0 Ok

Tell Postfix who the recipient of the mail is:

rcpt to:<[email protected]>

Postfix accepts that:

250 2.1.5 Ok

Then we are ready to send the actual mail:

data

Postfix agrees and tells us we can send the actual mail now and end our input with a dot on an empty line:

354 End data with <CR><LF>.<CR><LF>

Okay, type in the mail:

Hi John,

just wanted to drop you a note.
.

Postfix tells us it has received the mail and queued under a queue ID:

250 2.0.0 Ok: queued as AK782JKD4

Thanks, Postfix, we are done:

quit