Exchange 2013 has a 1300-ish limit on the number of allowed IPs we can set in the list (the limit is on the corresponding AD attribute actually). Here are a few tips to workaround this limitation:
- create another receive connector with remaining IP addresses with the same set of permissions.
You get another 1300 ~ IPs that can be added.
- consider consolidating those IPs into supernet ranges. There are some good calculators you can use online that will do that for you.
For example instead of
=> One entry – 3 IPs
Thanks to Akshay Katti (PFE India) and Richard Timmering (PFE US) for these !