I was receiving all the new registration requests by email. But since few days back, there is no email being received and many users are pending. I see them, when I go to inactive users, otherwise I get no info if some one is registered or not.
I am using xoops 2.5.0
What went wrong?

All the options remains unchanged and same as previous when email was being received, but no more.

If you didn't change anything on your end, then probably your host updated something on the server. You better check with them.