First I created a ~/.mailrc file containing:
set smtp-use-starttls set ssl-verify=ignore set smtp=smtp://$SMTPSERVERMYISP:587 set smtp-auth=login set smtp-auth-user=$SMTPLOGINACCOUNT set smtp-auth-password=$SMTPLOGINACCOUNTPASSWORD set from="$MYEMAILADDRESS ($MYNAME)"
Then sending an email is just as simple as:
Then give the subject and start typing your message. Sending will be done by pressing CTRL-D.