[Koha] Koha 21.11.10 version, New Patrons email notice sending problem.

Good morning, I'm looking for tips to solve a New patron email notice sending problem. I noticed that Koha 21.11.10 version, New Patrons email notice only does not send, But book check-in, check-out, book renewal notification etc are working properly. -- Thanking you.. Librarian, MAMCET <http://mamcet.com/> Trichy-Chennai Trunk Road, Siruganur, Tiruchirappalli-621 105.