Reloading confs

[Scott Silva]

Logan Shaw spake the following on 8/24/2006 4:48 PM:
> On Thu, 24 Aug 2006, Craig White wrote:
>> On Thu, 2006-08-24 at 16:46 +0100, Colin Jack wrote:
>>> I presume I need to restart MailScanner every time a modify the .conf
>>> files?
>>> At the moment I do this by restarting sendmail ... is there an easier
>>> way? :)
> 
>> You shouldn't ever start sendmail (or restart sendmail) - you should
>> only restart MailScanner which in turns stops/starts sendmail for you.
> 
> I've never really understood this.  As far as I know, the
> dependency graph for proper operation looks like this:
> 
>     overall-mail-flow -> mailscanner
>     overall-mail-flow -> sendmail
> 
> But as far as I know, the graph doesn't contain either of
> these two relationships:
> 
>     mailscanner -> sendmail
>     sendmail -> mailscanner
> 
> Put another way, sendmail can happily run with MailScanner
> stopped.  It will just queue up messages in the incoming queue,
> and will possibly chew on delivering any messages remaining
> in the outgoing queue.  Things will never move from one queue
> to another, but that isn't sendmail's job.
> 
> Likewise, it also seems like MailScanner can happily run with
> sendmail stopped.  Any messages that are in the incoming
> queue will get processed and moved to the outgoing queue.
> No new messages will be placed in the incoming queue and
> messages in the outgoing queue will get delivered anywhere,
> but that's not MailScanner's job.
> 
> As a result, I don't understand why the two services are tied
> together in one startup script.  In fact, it seems definitely
> preferable to be able to restart mailscanner and leave sendmail
> running.  In fact, this is exactly what I do.  When I make a
> configuration change, I stop MailScanner ("bwahahaha...") but
> leave sendmail running.  I can then make sure that if one of my
> users has his MUA connected to sendmail and is in the middle of
> sending a 5 MB attachment, that won't be disturbed.  The users
> won't ever notice a broken connection or refused connection on
> port 587.  Remote servers won't ever notice a refused connection
> on port 25 and as a result try and hit my secondary MX.  It just
> makes more sense to me to leave sendmail up and let it queue
> messages if there is no reason to take that service down.
> It lessens the impact of making mailscanner changes.
> 
> So is there something I'm missing?  Is there a reason why it
> is the way it is?
> 
>   - Logan
Mailscanner takes care of scanning the mail. It starts sendmail differently
than if you start sendmail on its own. If you start sendmail and then start
MailScanner, you usually get errors about sendmail can't bind to port, already
in use.
If you start sendmail with service sendmail start, and leave mailscanner off,
sendmail will happily forward every mail that comes in, whether it is clean,
spam, or virus.

-- 

MailScanner is like deodorant...
You hope everybody uses it, and
you notice quickly if they don't!!!!