From: Jeremy Harris Date: Mon, 1 Jan 2024 21:08:13 +0000 (+0000) Subject: Docs: expand SRS info X-Git-Tag: exim-4.98-RC0~91 X-Git-Url: https://git.exim.org/exim.git/commitdiff_plain/43a1dac4b63c228775d92cdc2861b6f1e76c6f1f Docs: expand SRS info --- diff --git a/doc/doc-docbook/spec.xfpt b/doc/doc-docbook/spec.xfpt index 2c90ec5f3..493c094cd 100644 --- a/doc/doc-docbook/spec.xfpt +++ b/doc/doc-docbook/spec.xfpt @@ -42247,10 +42247,16 @@ The lookup will return the same result strings as can appear in .subsection "SRS (Sender Rewriting Scheme)" SECTSRS .cindex SRS "sender rewriting scheme" +.cindex VERP "variable envelope return path" SRS can be used to modify sender addresses when forwarding so that SPF verification does not object to them. -It operates by encoding the original envelope sender in a new +It can also be used to identify a received bounce message as +likely (or not) having been trigged by a message from the +local system, and for identifying dead addresses in mailing lists. +It is one implementation of a VERP (Variable Envelope Return Path) method. + +SRS operates by encoding the original envelope sender in a new sender local part and using a domain run by the forwarding site as the new domain for the sender. Any DSN message should be returned to this new sender at the forwarding site, which can extract the