Impossible to send from android smartphone with exchange 2019

[Laurent_RICHARD]

Hello,
I need your help, when I configure smartphone (samsung), I receive emails but impossible to send emails. I get a message: "Unable to send message".

I've recreated the ActiveSync folders in IIS but that hasn't changed anything.

Do you have a solution?

Version : Exchange 2019 cu14

[#2]

Did you use the Outlook app?

[#3]

@TAE YOUN ANN 

I use the Samsung Email application because with the Outlook application on Android, I get error messages when synchronizing the inbox.
Message: Synchronization with your Outlook failed for x items

[#4]

@Laurent_RICHARD 

Ensure that the email app or any Exchange-related apps used on your Android device are up to date. Sometimes, outdated app versions can cause compatibility issues, so updating to the latest version is recommended.