Email not being delivered to inbox

I have a user who can receive messages from everyone and being delivered to her inbox except for one user. Is there something in preferences that might cause this and can it be reversed

Subject: email not being delivered to inbox

Neema,

Check the mailrules enabled for this mailbox. I ever had related problems and noticed that ENABLED mailrules deleted don´t stop to wotking even after rule deletion.

I hope it helps,

Willian