I have to send a mail when stage changes with a delay of some specific time. For example, in my case, I have to send mail after 10 minutes of stage changes. The time should be configurable. I have try to achieve this by making force parameter to false as below:-

self.env['mail.template'].browse(template.id).send_mail(self.id, force_send=False)

And after that i have changed time intervals of "Mail: Email Queue Manager" template in scheduled action as per my requirement. In this case arises that When i send 2 mails lets say first mail on 11:30 and second mail on 11:33 and scheduled action will be performed on 11:35. So it sends both mails on 11:35 instead of sending mails on 11:35 and 11:38 respectively if i scheduled it at every 5 minutes after stage changes. So how can i achieve this?