Per
http://bugzilla.wikimedia.org/show_bug.cgi?id=12655 ...
On our newer, Ubuntu-based Apache configuration we've been using sSMTP
as a minimal local SMTP sending agent. This emulates the 'sendmail'
binary and simply passes messages off to a hub server with no local
queuing... but it's not without its problems.
sSMTP forces the message's 'From' header and the SMTP envelope sender
address to be the same, which causes some problems for us when that
'From' address is a user's offsite e-mail:
* Servers which validate SPF records may reject the messages outright
* In case of delivery problems, bounce messages will be sent back to the
user, possibly including the recipient's address which is supposed to be
kept private.
As a workaround for such configurations I've introduced a config var
$wgUserEmailUseReplyTo. When set, a wiki-specific address is used as
'From', and the user's address is put in 'Reply-To'.
This is uglier -- you don't see a clean 'Sender' column in your mail
client -- but mails will get through and private data won't get tossed
around inappropriately.
In the long term I'd like to see us either dump sSMTP (a local-only
postfix or something would work fine) or patch it to let the envelope
sender be set separately.
-- brion vibber (brion @
wikimedia.org)