Hi Gussy, thanks for your question. I'm Graeme, a Microsoft Community expert and fellow user.
You might have trouble sending may photos in one email depending on the file size limits imposed by your email provider, but I'll explain how to bundle many photos into one file anyway.
You can select all of your photos at once, then right-click and select Send To -> Compressed (zipped) folder. This will put all of your photos into one compressed zip file, which you can then easily attach to your email.
Hopefully that helps! Please let me know if you need further advice. Thanks!