When dealing with DNS-based white- and blacklists at significant volume, it is important to know which nameserver is actually being used – and it is often not trivial to identify this: The “inside” IP you see may be different from the IP(s) seen from the outside, or there may be several hops between the nameserver you are querying and the one seen from the Internet.
Removal of workaround-file for Postfix < 2.8 from download (updated)
dnswl.org will remove a workaround-file for Postfix < 2.8 from download on August 31st 2017. Continue reading “Removal of workaround-file for Postfix < 2.8 from download (updated)"
How many legitimate mailservers are there?
TL;DR: There are over 500’000 legitimate mailservers on the Internet. If you are not managing the IPs of your own mailservers at dnswl.org yet, you should do it!
Continue reading “How many legitimate mailservers are there?”