Hi Barry,
Thank you for your help. I searched the Events Calendar Pro forum for an answer to my question but didn’t come up with the ones you came up with. I will definitely vote for the one nearest to my wishes.
There are alternative ways I can think of. For instance I could use my Form plug-in (Formidable Pro) to create a very small subscription form and implement that on the single-event page. Formidable Pro works well with Mailchimp and I could then have a mailing list for each and every event in Mailchimp. But as you probably agree that is not the prettiest solution and would give our administration headaches as we have many events.
So an implementation in ECP would be very handy.
Thanks for your help and suggestions.