[CentOS] how to send mail from console

[Devin Reade]

If you're using a typical residential broadband ISP, outbound SMTP may also
be blocked by your provider as a mechanism to minimize mail abuse (spam).
In such a case, you will need to configure your MTA (sendmail or whatever)
to forward all mail through your ISP's official outbound mail server.

You can check this by issuing the command:

    telnet mx1.hotmail.com smtp

(Note the second 'smtp' argument there.)

If you see something like the following, then type "quit" (no quotes) and 
hit enter/return:

    Trying 65.55.92.152...
    Connected to mx1.hotmail.com.
    Escape character is '^]'.
    220 snt0-mc2-f42.Snt0.hotmail.com Sending unsolicited commercial or bulk e-mail to Microsoft's computer network is prohibited. Other restrictions are found at http://privacy.msn.com/Anti-spam/. Violations will result in use of equipment located in California and other states. Fri, 15 Jan 2010 08:54:58 -0800

If it doesn't do anything after "Trying 65.55.92.152..." or gives you
a connection refused, your ISP is blocking SMTP.

If your telnet appears hung, type control-] (right square bracket)
to get to the telnet prompt, then type "quit" (no quotes) and enter/return.

Devin