Sign-up rejects some email domains with "Invalid email format"

For anti-spam purposes, some email address domains may not be accepted on our main instance. Since we cannot easily make case-by-case exemptions, I'd like to ask you to use a different email address if possible. If you really do not have access to any other email address, please send an email to support@fluxer.app, since this is account-related and not specific to Fluxer as a software. Thanks!