Is there a way to set it up so [email protected] can be a lemmy account and also a mastadon account? I seen people using subdomains like [email protected] and [email protected] is this nessasary? Could u also set up a matrix account with the same [email protected]? If not what woukd be requured to change to make this possible?
No, not in the example that you’ve set up. The username is always @user@domain. This is like asking if you can have the same email address on Gmail and Hotmail or whatever. You can have the same user part, but not the domain.
People that have used [email protected] and also [email protected] is allowed because they’re different domain names.