[Dovecot] Quota by max file size

[Antonio Perez-Aranda]

Is It possible have a quota for max file size?

Per example, If the client try to save a very big mail as draft, p.e.
100M, and the limit of Exim configuration is 20M, the mail is really
saved in Maildir at sent or Draft but it can't be sent.

I think maybe is easy to create a plugin, get the saved stream size
and then if it is over quota max file size, abort save and notice to
use about the limit, but at first I want to know that really daesn't
similar exists.