Whats about sending down-/up- or both simultaneously per mailto:// from inside seafile?
Meanwhile i noticed, that a [send] link like my suggestion exists in v8. In v9 this button is gone. Why? At least pls reactivate this button. In an improved version a tick-marker to change between internal seafile mail-client and systemwide client would be great.
Or has the feature sadly been moved to the Pro version?