Anyone seeing Deferred/Failure deliveries on cPanel?

[CanUser]

Nearly all of my spamgourmet addresses use the xoxy.net domain.

All of my spamgourmet email is forwarded to an address at my personal domain (eg SpamGourmetMail@mydomain.com) which, via cPanel, is forwarded to a gmail address where I process all of my mail from several different sources.

I just checked the Track Delivery logs in cPanel and over the past month, I've got thousands of deferred message logs from messages that have been sent to SpamGourmetMail@mydomain.com. The result text for all of them is: smtp transport process returned non-zero status 0x0100: exit code 1

cPanel shows hundreds of failures, no doubt resulting from repeated deferred message attempts. The result text for all of the failures is: cancelled by timeout_frozen_after

I do receive lots of messages at SpamGourmetMail@mydomain.com but I can't help but think there is a bunch of stuff I'm not receiving, given all of the deferrals/failures.

I check my cPanel logs about once a month and I've never seen anything like this before. Anyone have any idea what's going on or where I should go to look for answers?