@Rakshith B Thank you for contacting us on Microsoft Q&A platform. Happy to help!
This seems to be a DPMUI crash on the MABS Server.
Request you to please check the below mentioned registry on MABS Server and change the value of it to 0.
Location - HKEY_Local_Machine\Software\Microsoft\Microsoft Dara Protection Manager\Notification
Name: SmtpAuthType
Value: 0 (in decimal)
Restart the DPM services on the MABS Server and try to setup the SMTP again on the MABS Server.
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