SMTP Email just stopped working

[SloppyGoat]

My boards' email function just stopped working for some reason. I am really stumped here. I have it set to use my SMTP with secure outgoing access. It just stopped working the other day and we have no email at all. I even restored my complete backup to a day before it stopped working and nothing! To me, that pretty much rules out the server altogether, right? Yet, sending using the same username through the same ISP's SMTP server works fine using Outlook. Anyone have any suggestions at all? I can't use PHP email because my SMTP does require a password for outgoing.

[Zachery]

If nothing changed at the vBulletin level, why wouldn't it be a server issue?

[SloppyGoat]

Because I restored a full image that went back to before the problem started. That pretty much rules that out. How can it be the server? At first, I thought maybe it was the last Server 2003 security update, so I went back before that too. No change. Nothing else has been changed since then, besides the update, and I went back to a date long before that was applied.

Something very strange...I just tried registering a test user, and I did receive the verification email! What is going on here? How can that work, but no other types of emails or notifications work? Just looking for ideas here. Like I said, I'm completely stumped. I haven't had any email problems for years.

If nothing changed at the vBulletin level, why wouldn't it be a server issue?

[Zachery]

vBulletin uses the same system for email. If one is going out, they're all going out. Where they are being stoped is somewhere outside of vBulletin.

[SloppyGoat]

It looks like it has to do with the address I'm using as my admin email. I changed it and it started working again. Apparently, it has been banned by some mail servers for some odd reason. I have no idea why, unless some spammers have been using my email address.

What's weird is, I was using a gmail address, and I never got anything back like this before. I don't even use this email address as the return. Is it my ISP that's changed something? Or has Gmail maybe changed something? Very strange...

The following message to <whatever@hotmail.com> was undeliverable.
The reason for the problem:
5.1.0 - Unknown address error 550-'SC-004 Mail rejected by Windows Live Hotmail for policy reasons. A block has been placed against your IP address because we have received complaints concerning mail coming from that IP address. If you are not an email/network admin please contact your E-mail/Internet Service Provider for help. Email/network admins, we recommend enrolling in our Junk E-Mail Reporting Program (JMRP), a free program intended to help senders remove unwanted recipients from their e-mail list: http://postmaster.live.com'

[SloppyGoat]

Apparently, Gmail has changed their spam filter policy, and they were all just caught in my own spam filter, even the test emails I sent myself! Weird! I sometimes forget that gmail is not just an smtp/pop server, since that's the way I use it.