mail_swaks []

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There are 2 main methods for sending/testing outgoing mail:

Telnet/nc
swaks

My favourite is using swaks as its easy to use and quick. You will probably need to install though:

SWAKS

Swaks can be found in the epel repository. Make sure you have this repo enabled and then run:

        
              # yum install swaks -y

Testing your local mail server

The following command tests your local mail configuration (postfix). This includes the relay that may be configured with it.

        
              swaks --to random_email@gmail.com --server 127.0.0.1 -from luke@example.com

Testing the relay host

The following command will send mail directly to the relay (for example sendgrid or mailgun).
Change “username” to the username you normally authenticate with to the relay host and you will be prompted for a password once you run the following command:

        
              swaks --to random_email@gmail.com --server smtp.sendgrid.net:587 --auth-user username -tls

Telnet

Command:

        
              telnet localhost 25

Response:

        
              Trying ::1...
Connected to localhost.
Escape character is '^]'.
220 cloud-server-03.localdomain ESMTP Postfix

Command

        
              HELO localhost

Response:

        
              250 cloud-server-03.localdomain

Command

        
              mail from: luke@localdomain.com

Response:

        
              250 2.1.0 Ok

Command

        
              rcpt to: luke@shirnia.com

Response:

        
              250 2.1.5 Ok
data
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