I wanted to test below scenario so I built an environment:
The below email came in from Anurag Mishra from india.nec.com
It needed moderation, had a few folks cc'd, and included attachments I
wasn't comfortable letting through.
However, Anurag, just based on the note sent it is important consider that
the NullPointerException appears to be coming from a custom processor. If
you can provide that full stack trace (text of it) then that will show you
the line it occurs on and likely the problem will be really clear to you or
whoever wrote that custom code.