That’s really odd, I’ve never heard of that before and I’ve never had any issues with Nexus but yeah. It looks like Nexus does block some email domains to prevent people from making tons of throwaway or alt accounts, which is kinda shitty.

Looks like GameBanana has some mods for New Vegas, but I am not sure if you will find everything you are looking for there. The vast majority of NV mods are hosted on Nexus. You could also trudge through the smut to see if you can find what you want on Lover’s Lab… but I wouldn’t recommend it.

I know my Nexus account is registered under a Gmail account if you want to try making a throwaway Gmail. Hopefully you’re able to find what you’re looking for!