I believe this question is probably better suited for the Gmail Help website, since it's not specific to Firefox. Gmail works the same in any browser because it's simply a website.

Gmail offers a lot of ways to include multiple recipients: adding mutilple addresses to the "To" field; making use of the CC option; making use of the BCC option. They all have different pros and cons. The Write Better Emails website has a pretty good explanation of the differences between the two.

However, information on how they behave specifically in Gmail or how to use them on their platform is probably more readily available on the Gmail support website I linked above.

Hope this helps.

Thanks for getting in touch and I’m sorry for not making my query clearer. I want to send a string of emails of different dates from one recipient to a single different recipient. I am told Chrome have an extension described as multi forwarding where you can select the emails you want to forward and send them all to another address hence my getting in touch with Firefox support to see if there was an equivalent

@Granddad Seaside unfortunately firefox AFAIK doesn't create addons or help with other Addons developer support beyond their defaults install. That is best forwarded to the Addon developer to further assist your request.

So you don't have an equivalent to the one on Chrome....