VERP
Variable Envelope Return Path: giving each recipient's copy its own envelope sender that encodes the recipient, so any bounce identifies the failed address without parsing.
What it means
With VERP, a list at origin sending to user@domain uses an envelope sender such as owner-listname+user=domain@origin. Whatever comes back to that address, however badly formatted, can only be about that recipient. The idea was popularised by the qmail MTA and the ezmlm list manager, and Postfix supports it on request.
VERP requires one copy per recipient, since each copy has a different envelope sender. The domain of the envelope sender stays the same, so SPF and DMARC alignment are unaffected; only the local part changes.
Example
MAIL FROM:<owner-news+ana=example.net@lists.example.com>Related terms
Sources
What this definition rests on. The wording is ours; the facts are theirs.
- Postfix VERP Howtopostfix.org
- D. J. Bernstein: Variable envelope return pathscr.yp.to
All 432 terms in the glossaryThe wiki: blocklists and bounce codes