Re: [exim] SMTP timeout while connected to <x> after sending…

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Author: Sujit Acharyya-Choudhury
Date:  
To: Exim-users
Subject: Re: [exim] SMTP timeout while connected to <x> after sending data block
On 2008-05-12 09:17, James Green wrote:
> Tom Kistner wrote:
>
> > Wedged TCP connections after some 10-500k of data usually point to
> > window scaling problems. But since you already turned that off (on

the
> > sending server?), I guess it is a dumb snort-like traffic mangler

"IPS"
> > that generates false positives. Try to get a contact on the

receiving
> > side. :)
>
> Bizarrely, this is happening with several receiving hosts -- I'm
> becoming more convinced this isn't an issue with my mail server
> configuration, but on the other hand it's not an issue I've run into
> anywhere else.
>
> After a bit more googling I've tried fiddling with
> tcp_workaround_signed_windows as well as tcp_window_scaling, but no

joy
> -- any further suggestions would be most welcome, although I fear this


> issue is rapidly moving away from on-topic for an Exim mailing list.
>
> All the best,
>
> James
>
>


We are seeing this kind of problem with some sites - so far only 4 or 5
have come to light.  I am running SLES9 and do tcp_window_scaling=0 in
/etc/sysctl.conf how will that affect e-mail delivery and receipt in
general?  The problem we are having is if the message size is > 32kb.
And our tcp_wmem has the following value:
4096    16384   131072


I know it is a bit Out of Topic - but I am sure somebody can give me
some idea?

Regards

Sujit Choudhury


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