Detailed attachments in mail log?

I am away from home so I have not read all my email from the
21st onward.  So, please forgive me if I have already asked
this and it was answered.

I have noticed that sometimes the total detail of an
attachment is expanded in the mail.log which can cause a LOT
of unnecessary stuff to be recorded.  Is there a way to turn
this off?

I had not seen this before last week, so I don't know when
it started or why.  We are running the beta version and I am
thinking this was somehow turned on in that.