Hello all
I think this problem has been raised before, but all the solutions did not find a solution to my problem
When I send an e-mail and the subject title is in English, the e-mail is sent normally without any problems.
But when the writing language is changed to another language, Arabic, for example, (mail delivery failed: returning message to sender from the opposite party).
This is with regard to the mail subject title only and not the content of the mail. Errors are not shown
The trace of the error inside the mail server indicates the following (AES128-GCM-SHA256:128 CV=yes: SMTP error from remote mail server after end of data: 550 Subject contains invalid characters.)
Any suggestion would be most welcome