Don’t use “Outlook (new)” in #Windows 11. I just did a tcpdump and looked also at my #mail servers when setting up an account in there. The mail client only spoke with Microsoft-servers, never with my mail-servers and I saw on my mail-servers only connections from Microsoft-IPs.
@nielsk this can be extended to don't use outlook (any), and don't use windows 11. I appreciate many folks have no choice.
I'm not some militants anti MS nutter though: Word v6 through to office XP was excellent, and i still like windows 10 when I have to run things that aren't available in other environments.
This redirecting your mail traffic is just nasty though, means your server creds have been exported (along with all your email, obvs).