Allow a VERP "bounceprefix" that's not exactly 4 characters

[Aaron Wells]

Mahara has a VERP system to identify users whose emails are bouncing, and disable sending to their email address. It uses a $cfg->bounceprefix setting to generated the VERP address; this is the part of the email that comes before the VERP stuff.

Currently, it arbitrarily forces this prefix to be exactly 4 characters, but there doesn't appear to be a reason for this, except that the process_email() function contains a lot of calls to substr() with hard-coded offsets that assume the prefix is exactly 4 characters.

I want to change this so that the prefix can be any length. The reason for this, is so I can use "verp+" as the prefix, which in our mail system will forward them all to the "verp[at]mahara.org" mailbox. And that will make it very easy for us to configure the IMAP-based bounce handling system.

[Aaron Wells (u-aaronw)]

https://reviews.mahara.org/2802

[Mahara Bot (dev-mahara)]

Reviewed: https://reviews.mahara.org/2802
Committed: http://gitorious.org/mahara/mahara/commit/db9c79bddf3f5bb8f4909bf09c18d41fd136f5d0
Submitter: Robert Lyon (<email address hidden>)
Branch: master

commit db9c79bddf3f5bb8f4909bf09c18d41fd136f5d0
Author: Aaron Wells <email address hidden>
Date: Fri Dec 13 15:24:06 2013 +1300

Allow a $cfg->bounceprefix that's not exactly 4 characters

Bug 1261231

Change-Id: I82d8169e41dcca65c214fdfec954086eba8fc6c8