using command line mail

Simply mail to recipient,

$ mail RECIPIENT

Enter subject, press enter, and type mail content. Ctrl + D to finish.

To include content from a text file, for example, msg.txt, simply enter ~r ./msg.txt at the first line of the mail content.

$ mail RECIPIENT -c CCPERSON

To list mail headers in inbox

$ mail -H

To list mail saved msg headers in mailbox (~/mbox)

$ mail -F

Inside mail console (don't really know what to call exactly), you can use h to list again mail headers, and enter any number to read specific mail.