Add string.

en.json

@@ -32,6 +32,7 @@
         "resend": "Resend verification.",
         "cancel": "Cancel request.",
         "check_mail": "Check your mail.",
+        "email_delay": "Please allow up to 10 minutes for it to arrive.",
         "check_spam": "Please check spam if you can't find it",
         "open_mail_provider": "Open {{provider}}",
         "successful_registration": "Successfully registered!",