Wow, I just noticed this game is made with Godot. How do you check the email format?
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Hi, I have list of popular domains, around a hundred.
When submitting email, I search for "@" in my input window. If it's there, I use .substr method to get part of string from "@" till end, this will give me domain. Then I verify that domain exists in email list and also the length of input (if no character before "@", this should not work). If all conditions met, popup is closed and you go on :-)