Many thks for your reply which, sorry to say, did not work, maybe because of my lack of
expertise in computer navigation.

However, you will be pleased to know that I have managed to find a solution after long and tiring hours of trial and error.

In short, the method consists of the following procedure:

1. Select COMPOSE in G-mail.
2. Leave the TO field blank.
3. Click ADD bcc
4. Enter all the recipients' email addresses in the bcc field.
5. Click SEND

With kind regards and my thks as always.

Joe