NPAworldwide began experiencing intermittent email delivery issues from our Outlook account about a week ago. After some investigation, we have learned that one of the Microsoft 365-owned servers that routes our email has been blacklisted by a spam filtering company called SpamCop in response to a high volume of spam coming from that particular server.
Rather than block the offending email accounts, SpamCop blocks the entire IP address, which prevents a lot of legitimate email from being delivered. This is an aggressive spam filter. If your IT provider uses SpamCop, please contact them and ask for email from @npaworldwide.com or @membernova.email to be delivered, even if it is being routed from a blacklisted server. Unfortunately, this has been an ongoing issue for the better part of a month with little response from Microsoft. You can learn more about the SpamCop blocking list here: SpamCop.net - Blocking List ( bl.spamcop.net )