Hi [mention:c63411cc9f194e348003e699b0ce31a5:e9ed411860ed4f2ba0265705b8793d05],
Sorry for the delay in the answer, it took us much longer than expected to verify our answers.
For your first question, the help page is correct. “Any” won’t work for a specific upstream host.
To use a smarthost, ideally, you need to use the Smarthost settings on Email > General settings.
For your second question, nslookup should work. If you still experience issues, we advise you to post on the dedicated Sophos Firewall Discussion board on https://community.sophos.com/sophos-xg-firewall/f/discussions. Our community members should be able to help you resolve your problem.
