mailagent and MH

["Susan G. Kleinmann" <sgk@sgk.tiac.net>]

I have just begun using mailagent, and am hoping for some enlightenment
regarding its behaviour.

I fetch mail from my ISP using a line like:
popclient -3 -P ~/.my_password_file my_ISPs_mailhost

This mail is processed by my ~/.rules file, and messages which aren't 
automatically refiled as a result of matching one of the rules are then
stored in the file ~/mbox.sgk, which has the same format as 
/var/spool/mail/sgk.

Then I try to fetch mail messages from mbox.sgk into my MH inbox,
by executing:   
   inc -file ~/mbox.sgk

What's odd is that I often have to execute inc more than 1 time -- sometimes
2 times, to get all the files from mbox.sgk into +inbox.  For example, 
as a result of running popclient, I might see that 4 messages are being
obtained from my ISP.  Then if I run inc -file ~/mbox.sgk, I might see
one mail message (and none have been added to any of the folders that
match my ~/.rules).  If I run inc -file ~/mbox.sgk again, I might see
that same message, plus another 3 messages.  

Another confusing point is that even though my ~/.mh_profile says
   inc: -norpop -truncate -audit audit-file
the file mbox.sgk is not zero'd after I fetch the files in it.

Seeking advice,
Susan Kleinmann