Sendmail "Large Box" warning in system logs

[Eric]

Good morning again, all...

I have searched everywhere I can think of (google, dejanews, yahoo, 
sendmail.org, FC6 release notes, sendmail man page, others) (yeah, Tim, I 
really did, honest...) and can't find the answer.

I'm getting a warning in my daily system logs:

Large Mailbox threshold: 40MB (41943040 bytes)
Warning: Large mailbox: <user> (58339992)

(This particular user doesn't download his mail much.)  :-\

It appears to have something to do with something called 
"sendmail-largebox" but I can't find any references to that either.

We often get large quantities of mail on this server, mostly large attached 
files, and I'd like to either turn that warning off or increase it to 80 or 
100 MB.

Gone through all of the above plus everything I can think of in /etc and 
its subdirectories and don't see anything that looks on-point.

I'd like to search the archives of this list but couldn't find a way to do 
that.  Is there any way to do a search on the archives?