Question How to install Dovecot mail_compress module

[FutureX]

I have a few emails from a migrated client that are gzip compressed. Plesk/Dovecot will not open them and I get the error:
failed: Cached message size larger than expected (1888 > 1155, box=INBOX.Sent, UID=3) (read reason=)

Tech support showed me that they were gzip'd from the previous server and brought over as-is.

I've installed the zlib library and added this line to dovecot.conf
mail_plugins = $mail_plugins mail_compress

then restarted Dovecot, but now I get the error:
Error: Plugin 'mail_compress' not found from directory /usr/lib/dovecot/modules

How do I install the mail_compress module?

And then how to I add plugin line to dovecot.conf so it doesn't get overwritten on update?

I don't want to compress messages, I only want to decompress emails so they can be read by the user. but I see in the docs that I must use the mail_compress_save setting or the plugin will be disabled

mail-compress plugin — Dovecot documentation

Thanks!

 

[FutureX]

Has anyone had experience with this?

 

[FutureX]

bump

 

[charlie_hun]

Hello,
With Dovecot 2.4 this is the right format (you can check if the plugin installed in /usr/libexec/dovecot/modules/ folder):

protocol imap {
  mail_plugins {
    mail_compress = yes
  }
}

protocol pop3 {
  mail_plugins {
    mail_compress = yes
  }
}
# Increase memory allowed for imap as it costs more to read compressed files
service imap {
  vsz_limit = 1024MB
}