Outlook 365 - Sending Error 0x800CCC78

I am using Outlook 365 (Listed Version 15.0.4885.1001), POP/SMTP, and have no trouble receiving emails, however cannot send. I can still send from my browser access, and this problem has only occurred today (with no changes to anti-virus software, usage habits or software). The error message is displayed below:

Task *** Email address is removed for privacy *** - Sending' reported error (0x800CCC78) : 'Cannot send the message. Verify the e-mail address in your account properties.  The server responded: 535 5.7.8 [TPG-A02] Authentication denied. User *** Email address is removed for privacy *** is banned from using SMTP AUTH due to previous abuse'

Thank you for your help.

Check this link out: https://support.office.com/en-us/article/I-receive-a-550-553-or-relay-prohibited-error-when-sending-email-messages-65b494a4-0a15-433e-829f-e73651e0245e

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Question Info

Last updated October 21, 2020 Views 1,173 Applies to: