[Dovecot] Fixing Timestamps

I have a user with a lot of email (A LOT of email, probably over 500,000 emails). Recently, several thousand messages of his were lost, and I pulled them out of the backup archives (zip files containing each days emails in an mbox) that are created on his account and fed them into his procmail scripts and they were all processed just fine and ended up in the right directories.

Except.

The messages were from 6 months back, and the messages now show up in his mail client with the time stamp of the date they were restored, and not the date that shows up in the headers of the message.

Anything I can do?

-- I AM NOT A LICENSED HAIRSTYLIST Bart chalkboard Ep. AABF04