Would be a nice workaround for those using dynamic dns services.

I thought of this as well.

My DNS server went down and at the time I didn't have another server up so I wasn't able to receive the email to add my current IP into the list. I thought it would be a good idea to have it resolve the hostname on login if the current IP wasn't in the whitelist. This would reduce the length of the whitelist for customers with dynamic IPs as well.

It turns out, my email was actually set to gmail, and being forwarded to my other account. I did manage to login after I had setup a temp server for DNS so I could add it.