Outlook.com email stuck at outbox

Im running em client 10.1.4828 (9843340) on my MacOS 15.3.1 (24D70)

The problem:
My outlook.com email stuck in outbox in both of my Mac
This issue also happends on em client iphone client

Attempts:
I have tried disable & enable the airsync but it didn’t help
I haven’t tried remove & re-add this account as I have improt the gpg key which I don’t want to do it again.

Please let me know anything I can do to resolve this problem
It concerns me a lot as I use em client as my major email client

Thanks
Rick

Ich hatte das gleiche Problem auf meinem Windows-Rechner.
Lösen konnte ich es, indem ich das Outlook-Konto gelöscht und mit den Standardeinstellungen vom emClient neu angelegt habe.
Seitdem funktioniert das Senden wieder.
Gruß