emailing mulitple photos from my Mac

Hello, I am looking for a simple program/software which would allow me to send multiple photos via email. Most of my photos reside within Aperture but now also in Photos. Also, is it possible to rename the file names since often an explanation of the photo itself is in order. What I do now is this:

I export photos from Aperture onto the desktop, either into a folder or sometimes just onto the desktop. I then open up mail and attach that folder or photosd to the outgoing mail.

Oftentimes we receive an email from friends containing photos. They appear to be in the form of a PDF file or something like that which can be opened individually. When I inquire with my friends, pretty well all of them send them via their Laptop but within the Windows world. Surely there is a better way then what I'm presntly doing. Your help is appreciated.

Hans