Spam from "Contact Us"??
 

We're suddenly bombarded by spam that seems to be coming via our "Contact Us" link, as in this one:

Subject: Catholic Community Forum Contact Us Form - Site Feedback

This particular one is all in Russian, but the junk ranges from porn to sales solicitations, and we're getting hundreds daily. None is coming directly via email, but is all going through the host server. Is there a way to stop it? Is there a way that spammers can post the link itself?

Meanwhile, a second problem: We use a Gmail account for webmaster. Since moving to a new hosting service ALL mail generated through vB (registration confirmations, thread subscriptions, birthday greetings, etc.) are ALL going to the spam folder with the following error:

host smtp.mailchannels.net [34.210.243.185]
SMTP error from remote mail server after end of data:
550 5.7.1 [BFD] Sender prohibited by SPF

Is that a hosting problem? Our Contact Us is set to "sendmessage.php". Host suggests changing to SMTP, but we've never had the problem before.

Do you use the "Contact Us" feature at all? You can just disable it.
"Sender prohibited by SPF" is a host related issue, probably related to the SPF DNS records of your domain.

Actually...no, except when we get slammed with junk registrations and shut down auto-reg (which is on now, with all newbies going to the moderation queue.
I just deleted the "sendmessage.php" -- I'll see how that works to stop the spammers!

Also, thanks for the error information, Dave. That's what I thought I got from mailchannels FAQs. I'll get back with host tech support.

Try:

Admin CP -> vBulletin Options -> Site Name / URL / Contact Details -> Allow Unregistered Users to use 'Contact Us' -> No

What we ended up doing is installing Project Tools and use that as a sort of help desk. Then we point

Admin CP -> vBulletin Options -> Site Name / URL / Contact Details ->Contact Us Link to project.php

Instead of deleting sendmessage.php I would renamed it with a discreet name or just make the extension something like .hold so it does not get executed if stumbled upon. This way if you ever want to revisit it, at least it is there...

Project Tools? Can you tell me about it please?

Its an addon:
https://vbulletin.org/forum/showthread.php?t=270346

version 2.3.1 was the last release. It is not easily found and I have a copy if you want it.