I send out about a few hundred group emails at a time and most of them (not all) come back with this message Server error: '550 5.5.0 <> invalid address. They are broken down into 5 groups of 50 or less and I get this message Server error: '550 5.5.0 <email address here> invalid address. Any thoughts?
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Is it possible that some of the addresses are incorrectly entered in Outlook? There are LOTS of entries returned from a web search on your error message, many related to Outlook.
I second @WestCoasterBC comment about Mail Chimp. It protects both you, and Telus from being punished for sending spam volumes of email.
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