Some ISPs do that or the owner set their spam rules a bit too tight.
No specific cure is known given the light information.
Bob
I have a friend running Windows XP and using MS Outlook for their email. They can send/receive email just fine but when someone sends them email as part of a distribution list they never get it. When those same people send them email directly they do receive it. Since this has happened across several senders the problem seems to more likely be with my friend's setup. Any ideas on what might be going on?

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