Hi
If you having this error:
14:43:15","Error","General","0","ErrorMessage","SourceCode.Workflow.Common.SmtpMail","0 SMTP mail send failure: Verify the SMTP connection strings are correct and that SMTP is working properly. Exception: Mailbox unavailable. The server response was: 5.7.1 Unable to relay","anonymous","0.0.0.0","XXXXXXXXX:C:Program Files (x86)K2 blackpearlHost ServerBin","XXXXXXX","XXXXXXXXXXXX",""
Keep in mind that the "Unable to relay" error will occur when the mail server is not configured properly to relay. If the From or the To addresses don't belong to a domain that the mail server 'owns', then you are relaying which will result in this error.
Please check if the SMTP mail server was configured correctly.
I would also recommend that you contact your Exchange Administrator to assist in troubleshooting this issue as they may have applied certain restrictions on the forwarding of mail.
Regards
Thabiso
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