It was working before 2 days. Now all notifications failed. Approval not sent. telnet to smtp.office365.com on port 587 is working.

Log file showing the following :

([com.adventnet.servicedesk.utils.ServiceDeskUtil]|[SEVERE]|[137]: FAILURE :Problem while sending E-mail. : Mail sending failed.<br><br> Please report the problem to the system administrator. Support file will have the error trace to analyze the problem and which can be created at Support -> Create Support File.|
[13:23:53:858]|[01-26-2022]|[com.adventnet.servicedesk.utils.ServiceDeskUtil]|[SEVERE]|[137]: FAILURE :Error occured while sending.<br><br> Please report the problem to the system administrator. Support file will have the error trace to analyze the problem and which can be created at Support -> Create Support File.|)

I tested it with another SMTP and emails delivred normally.

Any idea what the problem is?