Email not receiving

Hi,
our web site hosted in dreamhost name abc.com. Suddenly 1 of our employee (suppose email address - a@abc.com) is not receiving any emails, but outgoing is ok. And there is no error while sending/receiving!!! POP3 is mail.abc.com

I’ve checked in the dreamhost, but no problem found…
any idea what kind of problem is it?

Check if they’ve changed forwarding rules or their Spam Assassin settings.

Maximum Cash Discount on any plan with MAXCASH

No change in spam settings.
All of us getting emails, except 2 those email addresses…
Quite confusing…