Plugin: Managesieve full MIME support (esp foreverypart)

[dms2]

We've recently started using mime: foreverypart in our sieve scripts and I note that the latest version of the managesieve plugin for Roundcube 1.4 does not support this, specifically the code is currently

'mime',                     // RFC5703 (except: foreverypart/break, enclose, extracttext)

Ideally I would like to request support for the foreverypart functionality in the plugin.

However current behavior is that if the managesieve plugin is used to edit a filter which is supported (e.g. vacation message) then when saving the new version of the filters the filter using mime/foreverypart is removed which is very unhelpful!

It would thus be alternatively helpful for an option that the plugin just ignores filters it does not understand rather than deleting them.