Multiple email notifications

Hello, I have been using EasyBlog for some years.
I am using the current standard release.
My subscribers are receiving more than one notification email. For instance, on a single blog post, individuals receive from 1 to 6 notification emails. i.e. some receive 1, others 3, others 4, others 5 and others 6.
I have checked the email server logs and the problem is that EasyBlog is sending the emails multiple times- separated in time by 3 to 10 seconds. The email server is not indicating any poroblem. The website is hosted in the USA on inmotionhosting and the email server is in Australia so I suspect there is some timeout in EasyBlog which might be too short.
I am using email on page load.
The email sever is longstanding (10yrs) with no other problems. Indeed, I tried another email server from another provider and had the identical problem.
I really need a fix for this as people are annoyed.
Any suggestions gratefully accepted.
Regards,
David Kerr
https://www.kerr.net.au