[lug] multiple relayhosts (postfix)

Zan Lynx zlynx at acm.org
Tue Mar 27 10:39:32 MDT 2007


On Tue, 2007-03-27 at 09:57 -0600, Ben wrote:
> I'm running postfix on our intranet and it sends all outgoing mail to an 
> smtp server with the config line:
> relayhost = smtp.isp.com
> 
> Our relayhost doesn't like large e-mails -- it just drops the connection 
> after 95% transmission and then postfix tries again since it never got 
> an error, just a dropped connection. The second attempt fails the same 
> way, and I've got an endless loop. A friend of mine opened up his smtp 
> server to me and I'd like to use it for large e-mails, but not for just 
> regular e-mails.
> 
> So, can I either:
> 
> a) have postfix use two relayhost, one primary and one if the first one 
> fails
> 
> b) configure postfix to send all e-mails over 10M to a second relayhost?

Your relayhost is being a bad mail server by not returning an error
message.  Or possibly it is sending one and your postfix is the bad one.
You'd need a network sniffer to see.

However, you are not going to find many email servers that will accept
10M emails.  10M is the default upper limit for most of them.  So, I'm
not sure what benefit you'll get by using a different relay.  Unless it
in turn only relays to specific hosts that you *know* are configured for
big email.  In which case, why use a relay host at all?

You might be better off looking for a system to strip and copy large
attachments and replace them with a unique URL link to a web server
holding the attachment.  If the strip&copy uses a MD5 or SHA1 to name
the attachment copy and link then you get the additional benefit of
eliminating multiple copies of 10M email attachments.
-- 
Zan Lynx <zlynx at acm.org>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 189 bytes
Desc: This is a digitally signed message part
URL: <http://lists.lug.boulder.co.us/pipermail/lug/attachments/20070327/15732906/attachment.pgp>


More information about the LUG mailing list