[CentOS] Help sought for email problem

My home server is running CentOS-7.1 I'm running postfix and dovecot on it. I collect email from a few sources with fetchmail and move it to ~/Maildir/cur/ with procmail.

Or at least, I did do this. For some reason procmail has stopped doing its job, and the email that I collect is finishing in /var/spool/mail/tim/

I can't work out what has caused this, or what the cure is. I haven't changed postfix or dovecot config files, or .procmailrc. I did stop and re-start postfix and dovecot on the server, which I haven't done for some time, so it is possible some earlier upgrade has come into play.

Any advice or elucidation gratefully received.