Hi @LcChnh-7604
I would like to confirm with you first:
Are you using Exchange Online (Office 365) or are you using Exchange On-premises as email service?
From the log it seems the application is connecting to port 25 on Exchange to send emails.
To me it should be the expected behavior.
Since port 25 doesn't require authentication (otherwise the server would be unable to receive anonymous emails), you may need to use port 587 instead to authenticate and send emails.
Here is also a link about how to configure POP3 and SMTP settings (applied to Exchange Online) : POP, IMAP, and SMTP settings
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