[Mailman-Users] Microsoft blocking our Mailman lists

Lindsay Haisley fmouse at fmp.com
Sun Oct 7 12:28:28 EDT 2018

FMP's mail and web server is a virtual server at Linode. We run half a
dozen Mailman lists or so, all opt-in lists for a couple of non-profits 
and small business customers, all of which have been running
successfully for many months. Today I got a large number of
unsubscription notices from one of our lists, all of them for addresses
at hotmail.com, msn.com and outlook.com. They contain the following

 hotmail-com.olc.protection.outlook.com []:
 >>> MAIL FROM:<aftm-bounces+clarkson-66=hotmail.com at lists.fmp.com>
 <<< 550 5.7.1 Unfortunately, messages from [] weren't
sent. Please contact your Internet service provider since part of their
network is on our block list (S3140). You can also refer your provider
to http://mail.live.com/mail/troubleshooting.aspx#errors.

Has anyone seen similar problems recently with Microsoft mail customers
who are Mailman list subscribers?

Lindsay Haisley       | "The first casualty when
FMP Computer Services |         war comes is truth."
512-259-1190          |            
http://www.fmp.com    |     -- Hiram W Johnson

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