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Diffstat (limited to 'doc/doc-txt/experimental-spec.txt')
| -rw-r--r-- | doc/doc-txt/experimental-spec.txt | 28 |
1 files changed, 28 insertions, 0 deletions
diff --git a/doc/doc-txt/experimental-spec.txt b/doc/doc-txt/experimental-spec.txt index 7bb17883c..f419bfedf 100644 --- a/doc/doc-txt/experimental-spec.txt +++ b/doc/doc-txt/experimental-spec.txt @@ -6,6 +6,34 @@ about experimental features, all of which are unstable and liable to incompatible change. +PRDR support +-------------------------------------------------------------- + +Per-Recipient Data Reponse is an SMTP extension proposed by Eric Hall +in a (now-expired) IETF draft from 2007. It's not hit mainstream +use, but has apparently been implemented in the META1 MTA. + +There is mention at http://mail.aegee.org/intern/sendmail.html +of a patch to sendmail "to make it PRDR capable". + + ref: http://www.eric-a-hall.com/specs/draft-hall-prdr-00.txt + +If Exim is built with EXPERIMENTAL_PRDR there is a new config +boolean "prdr_enable" which controls whether PRDR is advertised +as part of an EHLO response, a new "acl_data_smtp_prdr" ACL +(called for each recipient, after data arrives but before the +data ACL), and a new smtp transport option "hosts_try_prdr". + +PRDR may be used to support per-user content filtering. Without it +one must defer any recipient after the first that has a different +content-filter configuration. With PRDR, the RCPT-time check +for this can be disabled when the MAIL-time $smtp_command included +"PRDR". Any required difference in behaviour of the main DATA-time +ACL should however depend on the PRDR-time ACL having run, as Exim +will avoid doing so in some situations (eg. single-recipient mails). + + + OCSP Stapling support -------------------------------------------------------------- |