Email not being delievered

I am running the latest version of Virtualmin and CentOS 6 x64. Incoming mail (from any address) is not successfully being delivered to my inbox on Virtualmin. Outgoing mail works fine. When I send an email to my Virtualmin email address, hotmail thinks that it did send correctly, as I don’t get a postmaster. However, a few hours later (about 7 or 8) I got a postmaster from hotmail that says:

This is an automatically generated Delivery Status Notification.

THIS IS A WARNING MESSAGE ONLY.

YOU DO NOT NEED TO RESEND YOUR MESSAGE.

Delivery to the following recipients has been delayed.

  aman207@aman207.net

I checked the logs and there is nothing to suspect that email isn’t being delivered. Outgoing mail works perfectly fine. I did use the automated installation to install Virtualmin, if that helps.

So my question is, why is email from my hotmail address to my virtualmin address not being delivered, even though at first it seems as though it was delivered successfully.

For some reason:
your recipient’s email server temporarily rejects your message.
your recipient’s email server is temporarily down

Without more info from your mail.log cannot I am unable to say for sure.

grep aman207@aman207.net /var/log/mail.log

Are you sending email FROM or TO your system when you have the problem? That didn’t really become clear from your post, since you said “outgoing mail is working fine”.

So please reiterate, from where to where exactly are you sending mail, where in the logs do you see what, and from where did you get the “being delayed” report?