Hallo Peter,
vielen Dank für Deine Antwort und natürlich auch ein freundliches 'Hallo', da ich ja neu hier bin!
Ich habe durchaus eine Lösung gefunden, wie dieses Problem, mit dem sich anscheinend gar nicht so wenige rumschlagen gelöst werden kann.
Auf dem ersten Blick lässt das Addon Xnote nur das lokale speichern von Notizen zu, durch die FAQ bin ich aber auf folgende Lösungsvorschläge gestoßen, die ich hier gerne noch mal einfüge:
"Question: Could you store the notes directly in the e-mail so that the notes can be used across different computers when using IMAP?
Starting with version 2.2.1, you can configure the storage path for your notes. By default, notes are stored in the "XNote" folder in your Thunderbird profile directory. In order to access the notes on a different computer or to share them with other users, configure the storage path to a mounted network drive, e.g., using WebDAV, Windows Share / Samba, or NFS. Beware that this might have a negative impact on the performance of the message list (scrolling) due to the network latency and the way how the XNote column is implemented. Another solution is to save the notes in a Dropbox folder.
In order to change the storage location, use the advanced configuration editor (Tools – Options – Advanced – General – Config Editor...) to add the property "xnote.storage_path" (right mouse click – "New → String") and configure it with your desired path. If you already had some notes, don't forget to move them to the new location.
Similar to the previous option, you can store your whole Thunderbird profile on a shared network drive (requires appropriate configuration of "profiles.ini" in your Thunderbird user directory). Beware that this might have a big performance impact – depending on your network and the amount of data stored in your profile directory.
Another suggested option is to use some custom X-... header to store the note in the message header (it was reported that MailTags for Apple Mail does that). This will most likely not be implemented—unless someone contributes the necessary code."
Nachzulesen ist dies unter folgendem Link: http://www.froihofer.net/xnote/
Hoffe, dass andere Nutzer die auf einer Lösung dieses Problems hier fündig werden.
Viele Grüße
siglo