I only receive some faxes, and others are not delivered to me.

This issue has been reported by some users who can receive small-sized faxes (for example one-page faxes), but have trouble receiving faxes that are several pages long.

The first thing is do is make sure your mailbox has no size limit. If you have a limit on the attachment size, you will not be able to receive heavy attachments or faxes containing lots of graphics.