Portal Home > Knowledgebase > Email Related Issues > Frequently Ask Questions > Error - 550 not local host domain.com, not a gateway
If you get the error - "The message could not be sent...550 not local host abc.com, not a gateway", we suspect that you have not perform authentication setting in your mail client.
You can double check the account configuration in the MS Outlook/Outlook Express. You need to click on "My outgoing server requires authentication" check box in the Outgoing Mail Server setting.
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