Linux Ask!

Linux Ask! is a Q & A web site specific for Linux related questions. Questions are collected, answered and audited by experienced Linux users.

Feb 152012
 

Sending email using raw SMTP commands

Answer:

You can send email(s) by connecting to your SMTP server, and using raw SMTP commands.

E.g. assume your SMTP is localhost, listening port 25, enter the commands in bold

# telnet localhost 25
Trying 127.0.0.1...
Connected to localhost.localdomain.
Escape character is '^]'.
220 smtp.example.com ESMTP Postfix (Ubuntu)
helo localhost
250 smtp.example.com
mail from: john@example.com
250 2.1.0 Ok
rcpt to: mary@example.com
250 2.1.5 Ok
data
354 End data with .
This is a test mail
.

250 2.0.0 Ok: queued as BA2FD1DB96
quit
221 2.0.0 Bye
Connection closed by foreign host.

Jul 082010
 

Test if local SMTP server is running

Answer:

To test if a local SMTP server is running, you can try to ping the port 25

# echo -e "quit" | nc localhost 25
220 ubuntu ESMTP Postfix (Ubuntu)
221 2.0.0 Bye

If no SMTP server is listening

# echo -e "quit" | nc localhost 25
localhost.localdomain [127.0.0.1] 25 (?) : Connection refused