• The problem is that the relation needs to be fetched before we can test if item has an annotation, because we need the mimetype of the relations.

Akonadi::Relation MessageItemPrivate::relatedNoteRelation() const

-> we cannot fetch for every mail theire relations, because aof performance issue.

possible solution: with the creation of an annotation we save the status in Akonadi::MessageStatus. So we can check the availability of an annotation without need to fetch the all relations.