04-30-2007 07:32 PM
Untd.com (Juno, NetZero, Mybluelight.com) routinely blocks email from our Ironport by ip address. The reason Untd.com gives us for blocking our email is because of "open connections" left incomplete by our Ironport.
We use a filter to temporarily work around the problem to send email out another ip address for the domains that Untd.com manages. We then patch our Ironport or make some setting change and tell untd.com we've corrected the problem and within 24 hours or so they start allowing email from the ip address they had blocked.
Has anyone else had a similar experience?
We send a million and a half emails a month to the typical variety of email providers (Hotmail, Yahoo, Google, AOL, Comcast...) and Untd is the only one to ever block email from our Ironport for any reason.
05-03-2007 03:08 PM
How long are they saying the connections are held open for?
I'm nearly certain that a feature of AsyncOS is to leave the delivery connection open for 5 seconds after the mail finishes in an attempt to have a slight performance improvement if another message comes through for that same destination.
I would try convincing the untd.com adminstrators that their policy is a bit aggressive.
05-03-2007 03:46 PM
Thanks bvanzant.
You said "a feature of AsyncOS is to leave the delivery connection open for 5 seconds after the mail finishes". I will look into whether there might be an option to close delivery connections more quickly per domain. Might you know whether this is possible?
I agree that untd.com is being unreasonable... we send a million and a half emails a month all over and never have this issue with any other ISP's. Our mail list managers want to tell our subscribers to change ISP's.
05-03-2007 04:00 PM
As I was writing that response up I took a look through destination controls and the like and didn't see that option. I assume that's where it should be.
If one of the SEs here on the board doesn't know I'd fire through a request to IronPort support and see what they say. It's probably possible; there's little you can't configure on these machines.
05-04-2007 03:52 PM
According to response from the support engineer:
"the 5 seconds timeout is not configurable. We keep the
connection for 5 seconds longer for optimization in case there is another mail going to that same destination."
I'll come back to this Monday and look at it fresh...
05-04-2007 04:05 PM
I just looked through the code and the CSE is correct, it is not configurable.
09-24-2007 05:28 PM
United Online is notoriously stingy on their incoming mail policies. If you are sending any significant amount of mail to them, they will block you after only a handful of unknown users. You will remain blocked until you contact them. The best thing to do is to make sure you deliver to them very slowly with no connection caching.
09-25-2007 03:17 PM
The best thing to do is to make sure you deliver to them very slowly with no connection caching.
10-12-2007 04:33 PM
I can understand the attempt at improving performance, but maybe an option to use pipelining (if offered) might be a friendlier option.
~JasonG
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