The insert option is to insert a graphic image, such as a photo, into an HTML message. If you want to send multiple files, use the Attach option, which lets you attach multiple files to a message.

Thanks, very useful to learn that.

But I still cannot insert into the body of an email more than one image at a time. I can only select multiple images from a subdirectory and then drag them into the body of the email.

I'd like Insert, Image to allow insertion of multiple images.

It will not do that, as the intent is in creating an HTML message where the graphic being inserted is to augment the message, not populate a gallery. You will need to continue doing it manually.

Sorry, but I don't agree with this.

As the user, surely I should be free to insert as many images, photos as I choose?

No. That is true only within the constraints of the software being offered for your use. Thunderbird allows up to one at a time, so that is your limit. And, from my personal experience, that is the limit of other email clients: one at a time. What you want to do is outside the boundaries of other users, so adding the ability to insert a gallery into an email is not an offered feature. However, you're free to request that feature by going to connect.mozilla.org, signing in and clicking to the IDEAS section where you can post your recommendation to be able to insert a gallery of images with one click.

Insert multiple images by drag and drop from File Explorer. When you drag onto the Write window, there is the option to attach or append inline (see picture).

Yes thanks again David and sfhowes, I knew about the drag and drop but find inserting multiple selected screenshots far more convenient.

I'll post the suggestion at connect.mozilla.org

Ian