we upgraded RT4.4.4 to RT5.0.1 and send all mail from local through MS365 mail servers to our users and external recipients. We are located in germany and therefor use german umlauts in mail. Since we use MS365 server the mail encoding seems to brake and the german umlauts are not shown correct.
We have set:
Within the Webinterface everything looks fine.
I tested different mailserver and mailclients:
Gmail received mail through mailprovider ionos (not ms365)
internal HCL Domino Mailservers and Notes Client
In this tests every mail looks correct, no broken signs.
Outlook Client: Mail is send from RT through ionos and received through ms365 to outlook: mail has broken german umlauts
What can I do to solve the problems with RT5.0.1 and mailservers from ms365?