[cyrus 3.0] 20 delayed mailbox deleted limit?

[Bron Gondwana]

On Thu, Jun 9, 2016, at 03:02, Andre Felipe Machado via Info-cyrus wrote:
> Hello,
> At future release notes I read
> "Under delete_mode: delayed, only the 20 most recently deleted mailboxes are kept for any given name."
> https://cyrusimap.org/imap/release-notes/3.0/x/3.0.0-beta2.html
> Is there any configuration parameter to increase this limit?
> Why this limit is needed?

denial of service / space wastage protection.  There's no config option available right now.  I could be convinced to change it.

How would you suggest we protect against exploiting delayed delete to fill the server without going over quota?  Maybe a new quota field for "total mailbox usage including deleted stuff" that can be set to a high enough value that no reasonable user will ever hit it?

Bron.

-- 
  Bron Gondwana
  brong at fastmail.fm