I have hosted my mail server on AWS. I have now enabled Yubico OTP authentication, and everything is working fine.
However, when I tried to restrict my outbound rules on AWS, I blocked outbound traffic on port 443.
At this point, I noticed that Yubico OTP stopped working correctly.
I would like to know how I can configure a rule for port 443 to allow it to access the Yubico cloud properly.
Adding the IP address of api.yubico.com to the rule doesn’t seem to work.
Thanks