I had this happen to me earlier this year and the specific problem we had to fix was that the file being sent out was an XLS and it was a very large file, being sent to a job role. At this point, two solutions presented:
1) we could change delivery file to XLSX, or
2) we could keep the XLS and instead of a job role, send it to a real name/s.
I do encourage you to go to the helpdesk though, if this doesn't solve your problem.