However this will be useful for people who get this message and are missing emails:

If you invoke procmail with the -t switch (add -t to the options to invoke procmail) [already done in this article] then the mail will be delivered -- probably to a plaintext file at /var/mail/cyrus

When you fall back to going from postfix->cyrus and skip procmail, this is how to redeliver those "lost" emails:


sudo mv /var/mail/cyrus /var/mail/cyrus.sent; sudo cat /var/mail/cyrus.sent | formail -s sendmail -t -bm -v


This will move the spooled flat file to cyrus.sent (so that the next time you try this you don't just append to the cyrus mail file), and pipe the text of the file to formail, which will split it into individual messages and requeue it for delivery from the beginning of the entire mail chain (sendmail) so that it actually gets delivered. Once those mails are delivered, another round of server changes can be attempted.

Criss