On 17.2.2013, at 12.19, Michael Grimm <trashcan@odo.in-berlin.de> wrote:
On 17.02.2013, at 11:08, Timo Sirainen <tss@iki.fi> wrote:
On Sun, 2013-02-17 at 10:44 +0100, Michael Grimm wrote:
Although even if it does, other parts of Dovecot still use only the hostname part to guarantee global uniqueness of things. So better to have unique hostnames.
What parts of Dovecot would be involved? I'm curious because my production mailservers use identical hostnames in their jails ever since running Dovecot (starting 1.x).
Mainly that maildir filenames are used as GUIDs. If two have the same name, they are assumed to be identical. That's why the maildir filenames include the hostname in them, to make sure that the GUID is different even if two mails happen to be delivered at exactly the same time with the same PID and same size to two different servers. So pretty unlikely, but better to be safe. :)
Ok, that won't hit me for the time being because I am using mdbox.
It's basically the same with mdbox, except instead of using actual hostname it's using a 32bit hash of it. (So yeah, ideally there should be checks for detecting hostname hash collisions..)