FEATURE: If the email is verified, we can use that to find accounts

plugin.rb

@@ -69,12 +69,15 @@ class OAuth2BasicAuthenticator < ::Auth::OAuth2Authenticator
     result.name = user_details[:name]
     result.username = user_details[:username]
     result.email = user_details[:email]
-    result.email_valid = result.email.present? && SiteSetting.oauth2_email_verified
+    result.email_valid = result.email.present? && SiteSetting.oauth2_email_verified?
 
     current_info = ::PluginStore.get("oauth2_basic", "oauth2_basic_user_#{user_details[:user_id]}")
     if current_info
       result.user = User.where(id: current_info[:user_id]).first
+    elsif SiteSetting.oauth2_email_verified?
+      result.user = User.where(email: result.email).first
     end
+
     result.extra_data = { oauth2_basic_user_id: user_details[:user_id] }
     result
   end