maillscanner/postfix saturates bandwidth :-(

[Glenn Steen]

... Antother thought.... 2000 recipients on a handcrafted list....
That might mean the usual amount of "normal" backscatter (think
bounces, OoO and other less-than-well-working autoresponder schemes)
would add significantly to the load on the dsl. All in all, a bad
situation with only drastic measures to solve it.

Cheers
-- 
-- Glenn

On 24 September 2012 23:11, Kevin Miller <Kevin_Miller at ci.juneau.ak.us> wrote:
> Check the exchange server, and if there are any pending outbound monster sized messages in the queue still delete them.  Be sure to notify your users, of course.  Next delete them off the outbound postfix server so you can process normal mail uninpeeded.  Then, as others have suggested, put the 3.5 mb file on a web server or use something like dropbox (or better yet, build yourself a zendto server) and have your user(s) just send a link to the URL instead of sending the mail out  to 2000 folks.
>
>  ...Kevin
> --
> Kevin Miller
> Network/email Administrator, CBJ MIS Dept.
> 155 South Seward Street
> Juneau, Alaska 99801
> Phone: (907) 586-0242, Fax: (907) 586-4500
> Registered Linux User No: 307357
>
> -----Original Message-----
> From: mailscanner-bounces at lists.mailscanner.info [mailto:mailscanner-bounces at lists.mailscanner.info] On Behalf Of Harondel J. Sibble
> Sent: Monday, September 24, 2012 9:15 AM
> To: mailscanner at lists.mailscanner.info
> Subject: maillscanner/postfix saturates bandwidth :-(
>
> Had an odd situation that started Friday night at one of my clients running a mailscanner/mailwatch mail relay for their internal Exchange 2007 server.
>
> Basically the dsl connection they share with another office was saturated when the office admin did a mailout on friday to about 2000 of their subscribers, each email was about 3.5mb total with conversion overhead.  When I say saturated, I mean in both the upstream and downstream directions.
> According the admin who runs the multitenant network in this office, he was seeing a sustained 1.6mb/s INBOUND connection to my client's firewall while this was happening.
>
> I intially though that someone had hacked in and was injecting spam, but after upstream throttling of the connection and disabling all smtp traffic, I was able to review the messages in the postfix deferred queue and determine they were part of the mailout.
>
> At this point mailq was showing 14 messages with approx 100 recipients total, I could then re-enable smtp traffic (in/out) at the firewall level and emails would be fine sending and receiving, but if I did a postqueue -f, the connection would saturate again until I blocked the smtp traffic, then waited a couple minutes before re-enabling it and the messages went back to being deferred.
>
> I'm trying to figure out the best way to deal witih this moving forward, is there additional throttling I need to do at the postifx level or the mailscanner level or something else.  I was also surprised as my understand of postfix is that it does connection throttling by default.
> --
> Harondel J. Sibble
> Sibble Computer Consulting
> Creating Solutions for the small and medium business computer user.
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-- 
-- Glenn
email: glenn < dot > steen < at > gmail < dot > com
work: glenn < dot > steen < at > ap1 < dot > se