Office 365 is a line of online services made available by Microsoft, as part of the Microsoft Office product line. Of course, this includes the synonym of email clients – Outlook.
Or in other words every self-hosted mail providers worst nightmare… Well, to be honest, it is its own nightmare as well. It’s been a few months of people constantly complaining that even emails from Microsoft’ servers to Microsoft servers get marked as spam or don’t get delivered period.
Anyway, in the past few days, we seemed to be getting a lot of weird complaints regarding one of our web hosting servers and Office’s 365 services.
The error message was unclear, poorly translated to my native language and offered very few clues. The only thing that kinda pointed me in the right direction was the famous 550 error, that doesn’t tell much by itself.
After about an hour of Googling, I came across a sysadmin that had the same issues as me. Taking from what he has written down I quickly came to realise that the almighty Microsft has done it again. Another hidden change to their “email processing method”.
Simply put if the receiving server used outsource RBL’s (Spamhaus, SORBS, etc…) the Microsoft’s outbound server would simply disconnect. Now the issue is that most of webhosting providers do use some sort of RBL in order to fight spam since you know it’s kinda there for a reason.
What to do?
(If using cPanel/WHM) Simply browse to the “Access Lists” tab in “WHM >> Exim Configuration Manager >> Basic Editor” and add the list below (it includes both IPv4 and IPv6 addresses) to the “Trusted SMTP IP addresses” option:
13.71.151.88/32 13.76.138.63/32 13.78.120.69/32 13.78.120.70/32 13.78.120.99/32 13.78.120.159/32 13.80.22.71/32 13.80.125.22/32 13.84.178.101/32 13.84.218.185/32 13.84.219.100/32 13.84.222.249/32 13.87.36.128/32 13.88.17.54/32 13.91.91.243/32 13.92.181.66/32 13.92.236.241/32 13.93.164.45/32 13.95.29.177/32 13.95.30.46/32 13.107.6.156/31 13.107.7.190/31 13.107.9.156/31 23.96.241.70/32 23.96.251.50/32 23.96.253.65/32 23.97.78.94/32 23.102.232.134/32 40.69.185.117/32 40.76.54.117/32 40.81.156.153/32 40.81.156.154/32 40.81.156.155/32 40.81.156.156/32 40.83.120.174/32 40.83.127.89/32 40.83.185.155/32 40.84.2.83/32 40.84.4.93/32 40.84.4.119/32 40.84.145.72/32 40.90.218.196/32 40.90.218.197/32 40.90.218.198/32 40.90.218.203/32 40.112.144.173/32 40.112.145.113/32 40.113.91.234/32 40.117.229.133/32 40.117.229.194/32 40.124.8.53/32 51.142.213.184/32 52.163.93.38/32 52.164.121.65/32 52.164.124.124/32 52.164.127.6/32 52.168.128.89/32 52.168.177.42/32 52.174.56.180/32 52.178.144.25/32 52.178.146.67/32 52.178.147.210/32 52.183.75.62/32 52.184.165.82/32 52.187.78.144/32 52.225.223.43/32 52.233.242.192/32 65.52.220.46/32 65.55.239.168/32 94.245.117.53/32 104.40.178.127/32 104.40.179.160/32 104.40.211.46/32 104.42.225.143/32 104.42.230.91/32 104.43.21.58/32 104.214.107.57/32 104.214.144.62/32 104.214.146.199/32 104.215.28.42/32 157.55.145.0/25 157.55.155.0/25 157.55.227.192/26 168.61.149.234/32 168.62.104.83/32 168.62.106.224/32 168.63.92.133/32 207.46.73.250/32 207.46.140.244/32 207.46.141.38/32 207.46.216.54/32 13.64.196.27/32 13.64.198.19/32 13.64.198.97/32 13.64.199.41/32 13.67.59.89/32 13.76.218.117/32 13.76.219.191/32 13.76.219.210/32 13.91.61.249/32 13.91.98.185/32 13.93.216.68/32 13.93.233.42/32 23.97.61.137/32 23.97.150.21/32 23.97.209.97/32 23.99.109.44/32 23.99.109.64/32 23.99.116.116/32 23.99.121.207/32 23.100.86.91/32 23.101.14.229/32 23.101.30.126/32 23.102.4.253/32 40.69.150.142/32 40.76.1.176/32 40.76.8.142/32 40.76.12.4/32 40.76.12.162/32 40.85.91.8/32 40.113.8.255/32 40.113.10.78/32 40.113.11.93/32 40.113.14.159/32 40.117.144.240/32 40.117.151.29/32 40.118.211.172/32 40.121.144.182/32 40.122.168.103/32 65.52.148.27/32 65.52.160.218/32 65.52.184.75/32 65.52.196.64/32 70.37.97.234/32 94.245.108.85/32 104.41.207.73/32 104.42.231.28/32 104.43.140.223/32 104.45.11.195/32 104.46.38.64/32 104.46.50.125/32 104.209.35.177/32 104.211.54.99/32 104.211.54.134/32 104.215.146.200/32 104.215.198.144/32 111.221.111.196/32 157.55.177.39/32 157.55.184.223/32 168.61.146.25/32 168.61.149.17/32 168.61.170.80/32 168.61.172.71/32 168.62.43.8/32 168.63.18.79/32 168.63.29.74/32 168.63.100.61/32 191.237.218.239/32 207.46.134.255/32 207.46.153.155/32 2603:1020:0:7::4e1/128 2603:1020:200::682f:a1d8/128 2603:1020:201:a::2b1/128 2603:1020:201::3c4/128 2603:1020:201::5f2/128 2603:1020:300::33/128 2603:1020:400::26/128 2603:1030:603::3c9/128 2603:1030:603::6a/128 2603:1030:603::72/128 2603:1030:a02::118/128 2603:1030:a02::367/128 2603:1040:200::111/128 2603:1040:200::325/128 2603:1040:400::2f4/128 2603:1040:400::5d/128 2603:1040:400::5e/128 2603:1040:400::7b/128 2603:1040:401::57/128 2603:1040:401::c/128 2603:1040:601::1e7/128 2603:1040:601::2f/128 2603:1040:601::36c/128 2603:1040:601::4e/128 2801:80:1d0:1c00::/64 2a01:111:2003::/48 2a01:111:200a:a::/64 2a01:111:202c::/48 2a01:111:202e::/48 2a01:111:202e::190/128 2a01:111:202e::191/128 2a01:111:202e::156/128 2a01:111:202d::/48 2a01:111:2035:8::/64 2a01:111:f100:1002::4134:c0cb/128 2a01:111:f100:1002::4134:c440/128 2a01:111:f100:1002::4134:d93c/128 2a01:111:f100:1002::4134:d9ee/128 2a01:111:f100:1003::4134:36d5/128 2a01:111:f100:1004::4134:f0c8/128 2a01:111:f100:2002::8975:2c33/128 2a01:111:f100:2002::8975:2d11/128 2a01:111:f100:2002::8975:2d43/128 2a01:111:f100:2002::8975:2d98/128 2a01:111:f100:2002::8975:2db9/128 2a01:111:f100:2002::8975:2cbc/128 2a01:111:f100:3002::8987:320c/128 2a01:111:f100:3002::8987:342a/128 2a01:111:f100:3002::8987:3552/128 2a01:111:f100:3002::8987:358e/128 2a01:111:f100:4001::4625:609b/128 2a01:111:f100:4001::4625:61ea/128 2a01:111:f100:4001::4625:a065/128 2a01:111:f100:4001::4625:a1e3/128 2a01:111:f100:4001::4625:a248/128 2a01:111:f100:4001::4625:a4b4/128 2a01:111:f100:4002::9d37:c021/128 2a01:111:f100:4002::9d37:c08f/128 2a01:111:f100:6000::4134:a2af/128 2a01:111:f100:6000::4134:b0ba/128 2a01:111:f100:6000::4134:b84b/128 2a01:111:f100:7000::6fdd:50bb/128 2a01:111:f100:7000::6fdd:682b/128 2a01:111:f100:7000::6fdd:699d/128 2a01:111:f100:7000::6fdd:6b20/128 2a01:111:f100:7000::6fdd:6b76/128 2a01:111:f100:7000::6fdd:6cac/128 2a01:111:f100:7000::6fdd:6fc4/128 2a01:111:f100:8000::4134:902e/128 2a01:111:f100:8000::4134:941b/128 2a01:111:f100:8001::d5c7:8077/128 2a01:111:f100:9001::1761:91cb/128 2a01:111:f100:a000::5ef5:581c/128 2a01:111:f100:a000::5ef5:6c55/128 2a01:111:f100:7000::6fdd:6095/128 2a01:111:f100:a001::a83f:5c85/128 2a01:111:f100:a004::bfeb:8aa2/128 2a01:111:f100:a004::bfeb:8c89/128 2a01:111:f100:a004::bfeb:8cb8/128 2a01:111:f100:a004::bfeb:8deb/128 2a01:111:f102:8001::1761:4237/128 2a01:111:f102:8001::1761:4daf/128 2a01:111:f102:8001::1761:4f8a/128 2a01:111:f406:1::/64 2a01:111:f406:1000::/64 2a01:111:f406:1004::/64 2a01:111:f406:1801::/64 2a01:111:f406:1805::/64 2a01:111:f406:3404::/64 2a01:111:f406:8000::/64 2a01:111:f406:8801::/64 2a01:111:f406:a003::/64 2a01:111:f406:c00::/64 51.4.71.0/24 51.5.71.0/24 51.4.70.0/24 51.5.70.0/24 51.4.70.0/24 51.5.70.0/24 51.4.226.115/32 51.4.227.178/32 51.4.230.178/32 51.5.147.48/32 51.5.242.163/32 51.5.245.67/32 2a01:4180:2401::11f 2a01:4180:2001::234 2a01:4180:2401::33b 2a01:4180:2001::92 13.71.201.64/26 13.73.64.64/26 13.73.208.128/25 23.100.16.168/29 23.100.32.136/29 23.100.64.24/29 23.100.72.32/29 23.100.80.64/29 23.100.120.64/29 23.101.144.136/29 23.101.165.168/29 23.101.181.128/29 40.113.192.16/29 40.114.120.16/29 52.126.194.0/23 52.244.120.128/25 65.52.1.16/29 65.52.193.136/29 104.42.72.16/29 104.43.208.16/29 104.43.240.16/29 104.45.208.104/29 104.46.112.8/29 104.209.144.16/29 104.210.48.8/29 104.210.208.16/29 104.211.16.16/29 104.211.48.16/29 104.215.96.24/29 131.253.120.0/24 157.56.53.128/25 157.55.59.128/25 157.56.58.0/25 157.56.151.0/25 13.72.17.49/32 13.72.18.116/32 13.72.18.212/32 13.72.18.216/32 13.72.18.221/32 13.72.184.118/32 13.72.184.199/32 13.72.184.206/32 13.72.185.34/32 13.72.185.5/32 13.72.186.138/32 13.72.186.230/32 13.72.186.27/32 13.72.186.4/32 13.72.187.8/32 13.72.188.114/32 13.72.188.142/32 13.72.188.36/32 13.72.189.143/32 13.72.189.27/32 13.72.19.36/32 13.72.19.9/32 13.72.190.167/32 13.72.190.80/32 13.72.191.10/32 13.72.20.4/32 13.72.23.54/32 13.72.49.238/32 13.72.50.182/32 13.72.50.206/32 13.72.50.212/32 13.72.50.218/32 13.72.51.69/32 13.72.55.111/32 13.72.55.162/32 13.72.55.177/32 40.66.16.0/21 131.253.83.0/26 131.253.84.64/26 131.253.84.192/26 131.253.86.0/24 131.253.87.144/28 131.253.87.208/28 131.253.87.240/28 131.253.88.0/28 131.253.88.32/28 131.253.88.48/28 131.253.88.96/28 131.253.88.128/28 131.253.88.144/28 131.253.88.160/28 131.253.88.192/28 131.253.88.240/28 40.118.209.192/32 168.62.190.41/32 13.72.179.197/32 13.72.183.70/32 23.103.191.0/24 23.103.199.128/25 23.103.208.0/22 52.227.182.149/32 52.227.170.14/32 52.227.170.120/32 52.227.178.94/32 52.227.180.138/32 52.238.74.212/32 2001:489a:2202:c::/62 2001:489a:2202:4::/62 2001:489a:2202:2000::/63 104.212.50.0/23 2001:489a:2204:2::/63 52.127.88.0/21 104.212.44.0/22 195.134.228.0/22 13.72.185.126/32 13.72.20.247/32 52.127.82.0/23 52.127.240.0/20 13.72.179.48/32 13.72.188.8/32 52.227.167.206/32 52.227.170.242/32 52.244.165.19/32 52.247.174.184/32 13.71.201.64/26 13.73.64.64/26 13.73.208.128/25 23.100.16.168/29 23.100.32.136/29 23.100.64.24/29 23.100.72.32/29 23.100.80.64/29 23.100.120.64/29 23.101.144.136/29 23.101.165.168/29 23.101.181.128/29 40.113.192.16/29 40.114.120.16/29 52.126.194.0/23 52.244.120.128/25 65.52.1.16/29 65.52.193.136/29 104.42.72.16/29 104.43.208.16/29 104.43.240.16/29 104.45.208.104/29 104.46.112.8/29 104.209.144.16/29 104.210.48.8/29 104.210.208.16/29 104.211.16.16/29 104.211.48.16/29 104.215.96.24/29 131.253.120.0/24 157.56.53.128/25 157.55.59.128/25 157.56.58.0/25 157.56.151.0/25 13.72.17.49/32 13.72.18.116/32 13.72.18.212/32 13.72.18.216/32 13.72.18.221/32 13.72.184.118/32 13.72.184.199/32 13.72.184.206/32 13.72.185.34/32 13.72.185.5/32 13.72.186.138/32 13.72.186.230/32 13.72.186.27/32 13.72.186.4/32 13.72.187.8/32 13.72.188.114/32 13.72.188.142/32 13.72.188.36/32 13.72.189.143/32 13.72.189.27/32 13.72.19.36/32 13.72.19.9/32 13.72.190.167/32 13.72.190.80/32 13.72.191.10/32 13.72.20.4/32 13.72.23.54/32 13.72.49.238/32 13.72.50.182/32 13.72.50.206/32 13.72.50.212/32 13.72.50.218/32 13.72.51.69/32 13.72.55.111/32 13.72.55.162/32 13.72.55.177/32 40.66.24.0/21 131.253.80.0/24 131.253.83.64/26 131.253.84.0/26 131.253.84.128/26 131.253.87.0/25 131.253.87.128/28 131.253.87.160/27 131.253.87.192/28 131.253.87.224/28 131.253.88.16/28 131.253.88.64/28 131.253.88.80/28 131.253.88.112/28 131.253.88.176/28 131.253.88.208/28 131.253.88.224/28 2001:489a:2200:500::/56 40.118.209.192/32 168.62.190.41/32 23.103.191.0/24 23.103.199.0/25 23.103.204.0/22 52.181.167.91/32 52.182.95.219/32 2001:489a:2202::/62 2001:489a:2202:8::/62 2001:489a:2202:2000::/63 104.212.48.0/23 2001:489a:2204::/63 52.127.64.0/21 52.180.255.180/32 52.181.163.42/32 104.212.32.0/22 104.212.60.0/23 195.134.240.0/22 52.127.80.0/23 52.181.164.39/32 52.182.95.191/32 52.127.72.0/21 103.9.8.0/22 42.159.7.156/32 42.159.4.68/32 42.159.4.200/32 42.159.133.17/32 42.159.132.138/32 42.159.135.78/32 171.111.154.0/24 115.231.150.0/24 175.6.10.0/24 101.28.252.0/24 211.90.28.0/24 123.235.32.0/24 180.210.229.0/24 182.50.87.0/24 42.159.7.156/32 42.159.4.68/32 42.159.4.200/32 42.159.133.17/32 42.159.132.138/32 42.159.135.78/32 180.210.232.0/24 58.68.168.0/24 209.177.90.0/24 209.177.94.0/24 180.210.234.0/24 209.177.86.0/24 23.236.126.0/24 123.150.49.0/24 222.161.226.0/24 112.25.33.0/24 125.65.247.0/24 171.107.84.0/24 139.217.17.219/32 139.217.21.3/32 139.217.25.244/32 139.217.19.156/32 42.159.233.91/32 42.159.237.146/32 42.159.238.120/32 42.159.224.122/32 40.125.169.147/32 42.159.201.24/32 42.159.33.144/28 42.159.33.176/28 42.159.44.0/22 42.159.161.128/28 42.159.161.160/28 42.159.172.0/22 42.159.33.192/27 42.159.161.192/27 42.159.164.0/24 42.159.36.0/24 139.219.16.0/27 139.219.17.0/24 139.219.145.0/27 139.219.146.0/24 42.159.34.0/27 42.159.38.0/23 42.159.162.0/27 42.159.166.0/23 42.159.34.32/27 42.159.34.64/27 42.159.34.96/28 42.159.162.32/27 42.159.162.64/27 42.159.162.96/28 42.159.4.50 42.159.132.75 70.37.81.47 42.159.4.225 65.52.98.231 168.63.252.62 42.159.4.50 42.159.4.45 42.159.7.13 42.159.132.73 42.159.4.225 42.159.132.73 42.159.4.45 42.159.132.74 65.55.227.140 65.55.69.140 40.73.248.0/21 40.92.0.0/14 23.103.132.0/22 23.103.136.0/21 23.103.144.0/20 23.103.198.0/23 23.103.200.0/22 23.103.212.0/22 40.92.0.0/14 40.107.0.0/17 40.107.128.0/18 52.100.0.0/14 65.55.88.0/24 65.55.169.0/24 94.245.120.64/26 104.47.0.0/17 157.55.234.0/24 157.56.110.0/23 157.56.112.0/24 207.46.100.0/24 207.46.163.0/24 213.199.154.0/24 213.199.180.128/26 216.32.180.0/23 2a01:111:f400:7c00::/54 2a01:111:f400:fc00::/54 2a01:111:f403::/48 23.103.132.0/22 23.103.136.0/21 23.103.148.0/22 23.103.152.0/21 23.103.156.0/22 23.103.198.0/24 23.103.200.0/22 23.103.212.0/22 40.92.64.0/18 40.93.64.0/18 40.94.64.0/18 40.95.64.0/18 40.107.64.0/18 52.100.64.0/18 52.101.64.0/18 52.102.64.0/18 52.103.64.0/18 65.55.169.0/24 104.47.32.0/19 157.56.110.0/23 207.46.100.0/24 207.46.163.0/24 216.32.180.0/23 2a01:111:f400:7c00::/54 23.103.132.0/22 23.103.144.0/22 40.92.0.0/18 40.93.0.0/18 40.94.0.0/18 40.95.0.0/18 40.107.0.0/18 52.100.0.0/18 52.101.0.0/18 52.102.0.0/18 52.103.0.0/18 94.245.120.64/27 104.47.0.0/19 157.55.234.0/24 157.56.112.0/24 213.199.154.0/24 213.199.180.128/26 2a01:111:f400:7e00::/56 2a01:111:f400:fe00::/56 23.103.136.0/21 23.103.152.0/22 40.92.128.0/17 40.93.128.0/17 40.94.128.0/17 40.95.128.0/17 40.107.128.0/18 52.100.128.0/17 52.101.128.0/17 52.102.128.0/17 52.103.128.0/17 65.55.88.0/24 104.47.64.0/18 134.170.132.0/24 134.170.140.0/24 207.46.51.64/26 2a01:111:f400:7c00::/54
Yeah, I know… It’s a huge list. But it’s currently the most complete list of Microsoft’s outbound IP ranges you will find out there. It includes local IP’s (Germany, US, etc…), as well as other such as outbound IP’s used by Outlook.com.
Hope it helps!
In the future, I shall be posting more about Microsoft’s SNDS and JMRP so stay tuned!