Frozen notification process is not executed

Hi all

I configured the notification from from the designer.

Under "MailNotification" I set all paremeters as "SMTP" server and port, the default sender etc.

Also I assigned to my job server the server function "SMTP Host".

Now when I have a Frozen process, automatically is generated a "VID_Jobqueue_Notify_Frozen" process.

The Step process sendmail is execution status "True" but it doesn't start.

Note that the jobserver, are userd to send others email, and they are correctly sended.

Could you suggest me what may be the missmatched or missed configuration ?

Thank you very much and best regards