Very recently, I am no longer able to receive any attachments via email. This is effecting 2 separate domains as far as I know. I can send attachments fine, but accounts on these domains cannot receive any attachments. I have tried multiple different types of files (bmp, jpg, pdf, mp3 etc) in multiple different sizes from 900 KB to 6 megs, but no emails sent to my accounts are received. The emails themselves do not arrive, nothing at all. There are no errors received at either the senders or recipients email accounts.
I have turned off all spam filtering incase that could be an issue, but no other changes have been made.
Update: After running a few tests it appears to be a size issue. I sent a 3.5 MB plain text email to my account and it also failed.