NM: Error: Failed to save changes in MimeToMapi 0x80004005 (4313551)

Issue

In all mail files I move, I sometimes get 1 or more of these errors

! Error: Failed to save changes in MimeToMapi 0x80004005
! Error: Error converting mime to richtext (80004005)

The log says (verbose):
(...)
@V Entering SetDestinationFolder()
@V Exiting SetDestinationFolder()
@U Created Message [Binary Tree Evaluation Copy]JMI suce
@U Properties Saved.
@U Writing MIME body...
!U Error: Failed to save changes in MimeToMapi 0x80004005
!U Error: Error converting mime to richtext (80004005)

(...)

Do you know when it occurs as MAPI error messages are really not clear, it's hard to determine what's the error?

Cause

This is due to mail attachment being over the HUB Transport attachment Max Size

Solution

Change in transport hub receive connector (DEFAULT and CLIENT), the max attachment size or restrict the max attachment size within the CMTe Migration profile (Destination Options tab)