Is there a limit on Custom Domains for Short URLs?

Is there a limit on Custom Domains for Short URLs?

Hello!

I've added 2 custom domains for Short URL's to our Marketing Automation account. I am trying to add another custom domain, but now I can't figure out how to do so.

Is there a limit on how many Custom Domains we can use for Short URLs? Can I delete any of the previously added domains?

Thank you!