Sendmail on the command line:
$ sendmail emailaddress write body of message CTRL-D
The CTRL-D is a end of message code for standard-in.
enter body of message
This message is missing a useful TO:line as well as a subject. To create these you need to create a file or use a script.
$ vim email.txt
date: todays-date // not required
Body of message goes here
Then call sendmail with that file as an input:
$ sendmail -t email@example.com < email.txt
Or you can use the -toption to to tell sendmail to read the header of the message to figure out who to send it to.
$ sendmail -t < mail.txt
This will process the To: and CC: lines for you and send the mail to the correct addresses.
Or call from a script:
open (OUT,”|/usr/sbin/sendmail -t”);
print OUT “From: firstname.lastname@example.org”; ## don’t forget to escape the @
print(OUT “Date: “.ctime().”n”);
print(OUT “To: $emailn”);
print(OUT “Subject: $subjectn”);