I'm doing an D365 on-premise to online Data Migration. I'm getting a Generic SQL Error on the email job.

I have about 130K email records to load. My job successfully loaded over 100K but i received the dreaded SQL Generic error on the rest. I have cleaned up the fields that I don't need in the target, I removed all the lookups but one to check if the record was created or not and I'm hard coding the owner GUID which I'll later fix on an update job. I noticed the Description field in these emails had a ton of text but even removing that mapping has not helped. I'm even using a Create block to increase performance. First, does any have any tips on what the issue maybe? Secondly, there is a field name 'messageiddupcheck' which I get a warning on is this field even used and could it be the problem? Thanks