Outlook has me stumped

[Homer Simpson]

i noticed yesterday that i could not send an email out. outlook would error out trying to send (see pic below for error). i run my own dedicated webserver and use mailenable as my email server. all attempts at connecting via smtp to two different domains on that box stopped working. my personal (cox, my isp) email still works a-ok. at first i thought this was a mail server problem. ive gone through everything and all is fine. i even disabled stuff and made the box an open relay and i still couldnt get it working. outlook is setup correctly, no SPA, no ssl. ports all match on the client and server. smtp authentication is checked in outlook like always. webmail works, and sending mail via php works on the server. pop still works in outlook as im getting email in. checked other obvious stuff, disabled firewall on my computer and the server, checked IPSec (port 25 is still open).

this morning at work i was tinkering while it was slow. for giggles and grins i added a pop acct to my outlook (also 2k3, but setup for exchange) and BAM. works. i dont know what's different between my computer at home and my laptop (also mine but use at work). both are XP Pro SP2. both have the firewall enabled (disabling at home made no difference and enabled at work worked fine). both are up to date. in fact, my home pc was just formatted 2 weeks ago. afaik, nothing has changed over these last two weeks and both computers are configured exactly the same. im at a loss as to what the next thing to look at is...

error: click for outlook error screen shot

 

[mechBgon]

I could be completely off-target, but what's the stacking order on the Tools > Services > Delivery tab if you have such a thing.

 

[Homer Simpson]

nope, delivery tab is an outlook 2k thing and services is only there when you have exchange. im using 2k3 and no exchange at home. tools>email accounts.

the order they are processed in is 2 cox accounts then 3 im having issues with. when i do send/receive, i get no errors unless i have something in my outbox for the 3 accounts w/ problems. using the test account button in the acct setup is how ive been testing

 

[Homer Simpson]

argh! figured it out. COX is blocking port 25 at their routers unless its going to a cox mail server. found the info in the support site for cox. according to them, the policy had been in place for quite some time but only now is being enforced. they say they didnt tell anyone about this enforcement because its in our customer agreement and we should have known about it. what a bunch of butt monkeys. i wasted so much time trying to figure this out and a simple email from cox would have made my last two days far less aggrevating.