Hey all. New Guy on here, also a fairly new user to Linux. I know enough to get myself into trouble but not enough to consider myself an expert by any means.

Anywho, here's the situation. Our company has a dedicated Linux box (Runnning Redhat Enterprise 3.0). The sole purpose of this box is to run as a dedicated SMTP Server. The server is co-located through a different company which poses a number of problems, one of which is that the only interface I have available to me is "Webmin" *blech*.

In any case, the server has 2 connections, one "back door" connection to our dedicated Web Server and another connection to the web.

The purpose of this server is to simply process and send mail that comes in from the Web Server, nothing more, nothing less. This server receives huge amounts of e-mails on a regular basis (transfers about 40 gigs of E-Mail over the web a month). and is constantly under load.

The server has been running properly for about 5 months, but over this last weekend, the servers web connection died for a day. During this time, e-mails were still coming in from the Web Server, the end result? The SMTP Server crashed and locked the server.

Monday, the server was restarted and everything appeared ok at first, but after a couple of hours of use it was clear that SMTP processes were not being handled properly.

It currently appears as if all the E-Mails in queue to be sent were dumped into the "Defer" list, and now the server is so backed up that it doesn't seem it will ever catch up.

What I'm trying to find out is 2 things... first, is there anyway to dump or move the defer queue so that the server can at least handle its current e-mail load?

Also, where's a good place to go to find the optimal settings for our server?

We handle around 600 different domains, and can not specify every domain in the machine, but we need the server to be able to keep up the pace without backing up.

There's a lot more information than this, but I'd rather start with this and then get some suggestions, and if you have any questions of me, feel free to ask me.

As you can imagine, we need this situation resolved ASAP, so I hope all you linux guru's can help me. Thanks.

If you can connect into this system via ssh or some backdoor - as root, type:
# postsuper -h ALL deferred

The above command would put all e-mails currently in deferred state on hold.
See: man postsuper - for further options.
If you haven't done so already, I would start by reading the following online postfix documents that seem relavent to your problem.
Bottleneck Analysis
Performance Tuning

Scowles-

Thanks for that, I am in the process of running the postsuper command... it appears to be taking a while, but there are A LOT of e-mails built up in the queue, so I'm not too surprised.


I have those two articles you mentioned, and have started going through them, but part of the problem is that I can't run the qshape command on the deferred or incoming queues... I have let both run for well over an hour without any response back. As far as I can tell, I've got somewhere in the neighborhood of 5 - 10 gigs of e-mail built up in the various queues (from several days of receiving e-mails and not being able to send them).

I really don't want to dump them all, but I also can't troubleshoot the system or Postfix until they clear themselves out.

I will look through the rest of those two documents and see if there's anything in them that will help me out more... possibly with getting that queue emptied quicker.

Thanks, and I will post later with what additional infmormation I find.

hello redwolf,

it seems i am having same problem , so incase u find any solution plz post it as soon as possible. i have about 10000 mails waiting in queue not moving forward

= bye

Well, by doing the above, I have been able to get the queue flushed out enough that mail is starting to come more regularly, the system is still backed up, but getting better. I am in the process of optimizing the settings right now.

One other related question though. I notice that there are a large number of e-mails that go from the Dedicated Web Server, through the SMTP and back to the Dedicated Web Servers POP Server...

Is there anyway to tell redhat to route all SMTP E-Mail destined for [x.x.x.x] ip address through the private IP Address [192.168.1.1]? I'm sure there is an easy way to do this, but I am having a hard time coming up with the right way to word it in order to find my answer.

I think this will help immensely more by taking this e-mail away from the web connection that is heavily used and routing it through the private connection that barely is being used.

I will continue working and posting updates on this problem, along with which things helped the most for other users with similar problems.


Thanks again for any help, it is much appreciated.

Are you possibly asking about configuring the transport table? i.e.

mydomain.com :[192.168.9.2]

The above would relay any e-mail for mydomain.com to the MTA at 192.168.9.2. But postfix running on your web server would still receive the inbound e-mail, just not hand it off to the local delivery agent like procmail.

Well, sort of... but, not using the domain. Our Dedicated web server has 600+ sites on it, all the at times receive e-mail that loops from Postfix back through the Web Server. What I am trying to do is setup the machine so that any routing that should eventually end up at the ip address: (10.1.1.10, not the real IP obviously), is routed to 192.168.1.1 instead, so that it doesn't have to go out to the internet, and instead is transferred between the local connection between the two machines.

Well, the good news is that Postfix has finally gotten back to working as normal, now the problem is I have all that E-Mail that I previously held. What would the command be to remove those e-mails from the "held" queue and place them back in the active queue? Also, is there a way to place only a portion of them at a time so that I don't reflood the SMTP Server again?

Please see: man postsuper - I would think the -H (upper case) argument is what you are looking for.

As far as releasing some of the "held" e-mail (versus ALL at once)... you will probably need to wrte a shell script that extracts the queue ID for each held e-mail (using mailq) and then pipes a portion of those queue ID's to the postsuper -H command. The postsuper man page talks about using standard input for specifying queue ID's.

just curious. this is a newbie question.

What program is it in Red Hat enterprise is processing all the smtp transactions in this case?

It's probably sendmail.