D. J. Bernstein
Internet mail
SMTP: Simple Mail Transfer Protocol

The SEND, SAML, and SOML verbs

SEND, SAML, and SOML are just like MAIL. The only difference is that

MAIL requests delivery to the recipient's mailbox;
SEND requests delivery to the recipient's ``terminal'';
SOML (``send or mail'') requests delivery to the ``terminal'' if that is available, otherwise the mailbox;
SAML (``send and mail'') requests delivery to the ``terminal'' if that is available and to the mailbox.

This profusion of verbs serves no purpose; the concept of a mailbox is already broad enough to include any type of delivery that the recipient wants to set up. SEND, SOML, and SAML are rarely implemented in practice.