To be more exact, some Facebook mail servers are listed in the Composite Blocking List (CBL), including but probably not limited to these: outmail002.ash1.tfbnw.net – 69.63.184.102 outmail004.ash1.tfbnw.net – 69.63.184.104 outmail007.ash1.tfbnw.net – 69.63.184.107 outmail009.ash1.tfbnw.net – 69.63.184.109 outmail110.ash1.tfbnw.net – 69.63.184.110 CBL is not very informative, but writes: ATTENTION: If you are running IPSwitch Imail, or similar shared… Continue reading Facebook mail servers blacklisted by Spamhaus XBL!