This FAQ is designed to answer common questions about sending e-mail from MVS.
What are my options for sending e-mail from MVS?
What is SMTP? What is its purpose?
What is RFC822?
What is MIME and why is it important?
What does a SMTP data stream consist of?
How can I send attachments?
How can I prevent users from pretending to be someone else when they send mail?
How can I prevent users from pretending to be someone else when they send mail?
SMTPNOTE creates the from e-mail address using the TSO user's Userid. If a complete SMTP datastream was created by a batch job and sent to IBM's SMTP server, that piece of mail can claim to be from whoever it wants to.
Some companies have used JES2 exit 31 (SSI allocation) to restrict who can use the Writer name of SMTP, based upon the program name and SAF (RACF) userid.
SMTP-Send provides a verification exit that allows companies to verify or replace the sender's address based upon the SAF id, and Jobname and other criteria.

How does SMTP-Send insulate me from the various Internet Protocols?
Where can I get more information about the IBM SMTP Server?
Do I have to use the IBM SMTP Server?
My SMTP server doesn't recognize the @ character in my e-mail addresses. How can I send mail?
How can I get my SMTP Server to relay all mail to another SMTP mail server?
How do I prevent spammers from hijacking my IBM SMTP Server?
How can I tell who's sending e-mails?