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When we send mail to a specific email address, we get the error:<br />
&lt;mail.ourdomain.co.za #5.5.0 smtp;550 Previous (cached) callout verification failure&gt;<br />
I haven't seen this error before. What does it mean?
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When we send mail to a specific email address, we get the error:
<mail.ourdomain.co.za #5.5.0 smtp;550 Previous (cached) callout verification failure>
I haven't seen this error before. What does it mean?

Email Non-delivery Error

Interactions between email servers and clients are governed by email protocols. The three most common email protocols are POP, IMAP and MAPI. Most email software operates under one of these (and many products support more than one).  The correct protocol must be selected, and correctly configured, if you want your email account to work.

Email Protocols

Microsoft Outlook is a personal information manager from Microsoft, available as a part of the Microsoft Office suite. Although often used mainly as an email application, it also includes a calendar, task manager, contact manager, note-taker, journal, and web browser.

Outlook

Exchange is the server side of a collaborative application product that is part of the Microsoft Server infrastructure. Exchange's major features include email, calendaring, contacts and tasks, support for mobile and web-based access to information, and support for data storage.