Bring back email to note feature

[nebulade]

Due to some Cloudron platform changes sending email to meemo which get converted to notes was removed. However Cloudron does support this now again and so we should bring the feature back.

[gw3583]

Is this still planned?

[nebulade]

This is currently not being worked on but mostly due to time constraints. I am happy to accept a pull request for it though.