How to delete old Postfix+Dovecot / CentOS6 emails?

Question

Mail server

Good day to all!
Tell me how you can delete old letters (three years old) through the console.
df

Filesystem      1K-blocks          Used                  Available     Use %         Mounted on
/dev/md2       1905695580     1757628360     51256780     98%            /
tmpfs             16368860          0                       16368860      0%             /dev/shm
/dev/md1       507684              120876                360597      26%           /boot

df-hi

Filesystem     Inodes IUsed IFree IUse% Mounted on
/dev/md2      116M  1.7M  114M    2% /
tmpfs           4.0M     9  4.0M    1% /dev/shm
/dev/md1         128K    63  128K    1% /boot

Answer 1

find /mail/dir -type f -mtime +1095 -delete
/mail/dir directory with letters
-mtime +1095 older than 1095 days
-delete delete
first check the list of files for deletion something like this
find /mail/dir -type f -mtime +1095 -print

Answer 2

By date for all mailboxes
By term (over 12 weeks) for user [email protected]
Other options: https://wiki.dovecot.org/Tools/Doveadm/SearchQuery