Re: [exim] Too many concurrent SMTP-Connections

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Author: Tom Ray [Lists]
Date:  
To: Martin Justra
CC: exim-users
Subject: Re: [exim] Too many concurrent SMTP-Connections
Martin Justra wrote:
> Tom Ray [Lists] schrieb:
>
>> Martin Justra wrote:
>>
>>> Hello,
>>>
>>> I tried google for that problem but it didn't give me any helpfull
>>> hints. I'm running a debian server. About an year after the install it
>>> now begins to bring sometimes the message "421 Too many concurrent SMTP
>>> connections; please try again later"
>>>
>>> There are about 5-6 People on that machine that should not be the
>>> problem. I think that might be spamd or clamav because the load with
>>> spams had been increasing.
>>>
>>> Or how can I fix that problem?
>>>
>>> Thanks,
>>>
>>> Martin
>>>
>>>
>>>
>> Do you get this error when you try to connect and send mail to your
>> server? Or are you seeing this in the log file when you're server is
>> trying to connect to an outside server?
>>
>>
>
>
> I get the error when I try to connect and send mail through my server.
>
> Thanks,
>
> Martin
>
>

It means that there are to many open SMTP connections either incoming or
outgoing. The default is 20, you can raise that with the smtp_accept_max
command in your configuration file. Here's how it is in mine:

# This option unfreezes frozen bounce messages after two days, tries
# once more to deliver them, and ignores any delivery failures.

ignore_bounce_errors_after = 3d

# This option cancels (removes) frozen messages that are older than a week.

timeout_frozen_after = 7d

smtp_accept_max = 500

Also do a ps -ef from the command line and see how many open Exim
processes are running at the time. It doesn't matter if there are 20
people on the machine, if Exim is only handling 5 processes you're fine.