I need help urgently. Sorry for asking so many newbie questions.

I've migrated my vBulletin forums over to my new dedicated box. Everything has been set up fine. PHP recompiled with GD, PHP Accelerator installed. I then find out that vBulletin is unable to send out any emails. No email verification, no post notification, nothing. None of my custom emailing PHP script worked. On the previous dedicated box things were working fine.

I spent the past 4 hours trying to find out why. IMAP server is running fine. I proceeded to try the following:

Restarted IMAP server
Disabled SpamAssassin
Disabled SuExec
Allowed nobody to send emails out
Added ports 25, 26 to APF firewall

All this to no avail. I do note that IMAP does not appear to be compiled with PHP but that shouldn't affect PHP sending emails out.

I would appreciate any help or advice.

I would appreciate any advice.

If you check, in WHM, under -> EMAIL -> MANAGE MAIL QUEUE do the messages you tried to send show up... and if so, what are the reasons listed about why the messages couldn't be delivered?

This is odd. Some users ARE getting verification and notification emails, while others are not. Well, I am one who is not at all, not for any of my email addresses, including my home one.

I was receiving emails fine before moving to RS. Could RS mail servers be in a spam list? Any other ideas?

The only ones there are the emails that bounced back.

I do see the emails I sent out listed, but then they disappear, presumably they are sent. However, I never receive them.

The weird thing is some of my users are still getting emails from the site.

Could this be related to DNS issues? My DNS is still being propagated. Though I can see my site fine.

Okay, getting closer to the source of the problem.

Checking my mail queue again, this is the latest bounced email:

It says the domain name of sender address does not exist. How do I change the domain name of sender address???

It should be specified in my PHP scripts actually, not like that. In the meantime, I shall investigate further...

Fixed the problem.

It was a DNS problem after all. I used another domain name, and it fixed itself.

For future vB Admins with CPanel:

1) Disable SuExec
2) Disable the option that prevents nobody to send email - this is because enabling this will stop emails from being sent via vB.

You can still have SpamAssassin enabled.

It's all trial and error.

If you are using your own nameservers and you have not asked RS to do PTR records for the nameservers IPs, some servers will bounce them (my Ensim does). Once RS does the PTR records mail is accepted by other servers.

I think that was the problem. Once I changed to another domain hosted somewhere else, everything seemed to work. Thanks for letting me know.

Why would you disable suexec? What do you mean by you used another domain name doc?

Because I don't need it - I'm the only one using the server.

I'm using a different domain for my hostname, which is pointing via A Name to my IP. Seems to work well.