I have the same problem and hope someone can help. I'm also not receiving comments OR the backups. The comments show up in my spam folder, but not as a regular email, they show up as "mail delivery system" messages. The backups aren't coming through at all though. I use Google Apps for email, and don't have any idea how to fix it so that it accepts all of the above...

I'm having a similar problem. It's a fairly new blog so the backup files aren't terribly large. We're using Contact Form 7 and are receiving those emails, but not receiving notifications of new comments OR the weekly backups. Any suggestions?

I'm getting other notification emails from Wordpress, such as comment notifications and not using and mail-related plugins.

My backup files are just under 5MB and shouldn't be rejected due to size, but I'm fishing around now to see if that may be the case.

It sounds like your email application is failing, either because it's rejecting them (perhaps they're too large?), or mail is not correctly configured.

Do you receive other email notifications from WordPress, such as when someone comments?

Are you using any mail-related plugins, such as an smtp plugin?

I'm running wp 2.6.5 and ever since Nov.20ish (upgrade to 2.6.1 I think) backups aren't being emailed. Both manual and scheduled email backups get stored on the server, but not emailed or deleted from the server.

Any guidance or advice? I'd appreciate it very much, Thank you,
-Anil