From LedHed's Wiki
When setting up a mail server sometimes its handy to be able to test from the command line.
This can be accomplished with telnet or openssl
Telnet
telnet mx.server.tld 25
ehlo my.hostname Mail From: [email protected] RCPT To: [email protected] DATA From: [email protected] Subject: Put your subject here Place the body of your message here then place a period on a line all by itself to finish the body of the message .
Testing SMTP/TLS with OpenSSL Client
openssl s_client -connect mx.server.com:25 -starttls smtp
ehlo my.hostname Mail From: [email protected] RCPT To: [email protected] DATA From: [email protected] Subject: Put your subject here Place the body of your message here then place a period on a line all by itself to finish the body of the message .