/var/spool/mail question

Hello,

I have procmail-3.13.1 and sendmail-8.9.3 installed on my system.

I do not know if this is a procmail question specifically, but here
goes.

Where can I get a list of the 'Status' switches that are added to
messages in the mail spools (usually in /var/spool/mail) after the
messages have been read?

I see Status: RO, Status: O, or Status: x.x.x on messages that have
been read, but left in a particular user spool.  I am writing a script
that will purge my user mail spools of messages that have been there
for over three months and need to know what these Status codes mean.

I am not subscribed to the procmail list yet, so if you could, please
reply directly to otrcomm(_at_)wildapache(_dot_)net

Thank you,
Murrah Boswell
otrcomm(_at_)wildapache(_dot_)net