Product 

Problem Description:

User with smtp.office365.com gets failed jobs in the mail queue. The following errors are recorded in column ‘error_text’ of database table ‘queue_jobs’:

• Error in processing.The server response was: 5.7.3 STARTTLS is required to send mail 

Solution:

To resolve the issue, add the following to mailSettings configuration:

<mailSettings> <smtp> <network ... enableSsl="true" /> </smtp> </mailSettings>

Workaround:

See SR 7001389248 for more details.