I tried to use a contact us form, but got error messages that was not a proper email.
I used two different emails, and I can guarantee they were proper form. I took screenshots, but this shouldn't be hard to reproduce. This was on Android using the Chrome browser
I was able to reproduce this by pasting in an email ending up with some extra whitespace at the end. Just pushed up a hotfix that will clear out any whitespace. Does it work for you now?
You can also submit a ticket by emailing firstname.lastname@example.org