[Koha] patron notice

[vinod kumar]

I am using Koha 17.05.07 in debian 8 and Koha & mails are working fine in
this instance.
I upgrade it to new Koha 20.05.07 in debian 10, and suddenly circulation
mails get stopped. Overdues mails are working fine but check-in, check-out
mails are not working. When I checked there is no entry in message_queue
table for circulation. I don't know what is the issue.
Any point of help is highly appreciated.