[TriLUG] Procmail error in postfix

[Douglas Ward]

New postfix server that I rolled out last week.  Copied a large mailbox 150
mb to the server and now when I try to send the user a new message this is
returned:

<rhenderson at xyz.org <rhenderson at clergymail.nccumc.org>>: can't create user
output file. Command
   output: procmail: Error while writing to "/var/spool/mail/rhenderson"

Is this because I set up postfix in the default mbox format and there is a
size limit for the spool file?  Can I/Should I switch to maildir to fix
this?  Is there some kind of quota for procmail that I am missing?  Thanks!