A comment on Hacker News pointed me to the MECSA tool provided by the European Union.

MECSA stands for My Email Communications Security Assessment, and is a tool to assess the security of email communication between providers.

As I run my own email server, I was curious to find out how my setup is scoring. Here are the results, seems like I'm doing a good job :-)

Link to the full report for jaggi.info: https://mecsa.jrc.ec.europa.eu/en/finderRequest/f856486ecaf94dce5e8022c0a97c63b3

Recently named on my Debian server started to emit the following messages:

Dec 23 18:30:05 server named[1168203]: checkhints: view external_network: b.root-servers.net/A (170.247.170.2) missing from hints
Dec 23 18:30:05 server named[1168203]: checkhints: view external_network: b.root-servers.net/A (199.9.14.201) extra record in hints
Dec 23 18:30:05 server named[1168203]: checkhints: view external_network: b.root-servers.net/AAAA (2801:1b8:10::b) missing from hints
Dec 23 18:30:05 server named[1168203]: checkhints: view external_network: b.root-servers.net/AAAA (2001:500:200::b) extra record in hints

The reason for these warnings, is a IP change of the B root-server.

Debian is not ready yet with updating their dns-root-data package.
To fix the mismatching IP definitions on a Debian system, the current root zone definitions can also be updated manually from Internic:

curl https://www.internic.net/domain/named.root -s > /usr/share/dns/root.hints
curl https://www.internic.net/domain/named.root.sig -s > /usr/share/dns/root.hints.sig

Seems that after donating to Wikipedia there is a redirect to this page, which sets a cookie to no longer show the donation banners.