Hello, I continuously receive this error and wonder, if I can only change this on the server side or if I can alter settings in my emclient to continue syncing.
Do you have an Outlook account?
If you do have an eg: IMAP Outlook account, try removing and re-adding it as an Exchange account as i’ve read Googling around this fixes that problem if it’s an Outlook account.
https://www.emclient.com/em-with-microsoft-exchange
Note: Before removing any account backup eM Client via “Menu / Backup”. You can see when the backup is completed via Menu / Operations".