Error Meessage Email body not accepted

I tried to send a message and got the following error: Cannot send message (Email body not accepted with reason: "unexpected failure, please try later.

Does anyone know what is causing this?


send us logs please: go to menu Tools->Settings->Logging and check “SMTP” under the problematic account. Then restart eM Client, try to simulate the issue and send us (with reference to this topic) the logs using the same logging settings window. Thank you.