Email forwarding refers to the operation of re-sending an email message delivered to one email address on to a possibly different email address. The term forwarding has no specific technical meaning. Users and administrators of email systems use the same term when speaking of both server-based and client-based forwarding.

Email forwarding can also redirect mail going to one address and send it to one or several other addresses. Vice versa, email items going to several different addresses can converge via forwarding to end up in a single address in-box.