Compact or archive emails

Hey!

Is there a way to minimize or archive e-mails on server, a tool, command or smt ?
I'm asking since an email is like 10G each on server, some of them are from 5 years ago and don't need them on current server.

I found the folder locations where are stored on server and i see them.

/var/vmail/DOMAIN/EMAIL/cur

What do u suggest to do ?
Thanks in advanced!

Compress old mails with Dovecot (wish this was the default config)!
https://serverfault.com/questions/1007996/compress-old-emails-with-dovecot

thanks for info