So, looking through the forums, no one has actually gathered together a decent list of servers. That being said, custom map servers are next to dead. The only ones that run them anymore are youtuber's servers and mods, as well as TF2maps. Ever sense quickplay was added, custom map servers weren't necessary anymore, hardly even vanilla servers in GENERAL. You could just join a trusted server at the touch of a button, thus making US obsolete. So, this forum is for rounding together all of the findable IPs for servers dedicated to running custom maps, posting your own dedicated server that runs custom maps, as well as the previous versions of this forum that I didn't see.