Activation Emails Not Sending

[Tanabe]

I get repeated emails saying they haven't received the activation emails yet, even after a time period they still don't receive them. This has been going on for months and I know its not a hack because its been happening before I've installed some of the major hacks. Any ideas on what I should be looking at? I've changed hosting companies and yet this still happens so not really sure what could be causing this.

[G0F0RBR0KE]

Do you have your e-mail set up in the vbulletin options?

[Eikinskjaldi]

Have you checked your email system and seen if it is a problem with rejections? Servers tend to be set up to have the sender as "nobody@server.com" which a number if ISPs auto reject as spam.