Email alias
An extra address that delivers into an existing mailbox or expands to other addresses, without being a mailbox of its own.
What it means
In RFC 5321 an alias is expanded by replacing the address in the envelope with the address or addresses it stands for, leaving the rest of the envelope, including the sender, unchanged. That is the difference from a mailing list, which changes the envelope sender. A person may have several aliases delivering to one mailbox, and a role address may expand to a whole team.
An alias on the same system raises no authentication issue, since the message never leaves it. An alias pointing to an address at another provider is forwarding in practice, with forwarding's effect on SPF, which RFC 7960 discusses for DMARC.
Related terms
Sources
What this definition rests on. The wording is ours; the facts are theirs.
- RFC 5321, section 3.9.1: Aliasrfc-editor.org
- RFC 5598, section 5.1: Aliasrfc-editor.org
- RFC 7960, section 3.2.1: Aliasrfc-editor.org
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