Autodiscover.xml 400 bad request

Hi,

I have a few different nopcommerce sites and all have basicly the same configurations.
Just one one of the sites, I am getting flooded with error logs of a 400 bad request.

The error log details does not give me much to go on. No Full Message.

Log Level: Error
Short message Error 400. Bad Request
Full Message:
IP address: 196.61.###.##
Customer: Guest
Page URL: https://mysiteurl/autodiscover/autodiscover.xml
Referrer URL:

I have no idea what this could be or how to stop it.

check whether this IP is a bot from the IP look-up online tool.
if it is a bot you can disallow this path from robots.txt
if it is not a bot user you can block this IP from the firewall.
//Rashed