In full editor, go to File>save for web
Select JPEG in the drop-town for e-mail.
In the new size box, I ususally enter 800 px for the long side. Be sure that "constrain proportions" is ticked.
When you save as, give it another name so that you retain the original.
Thanks for the quick advice! I will try it out and see what I come up with.
email : firstname.lastname@example.org
You're welcome. Glad to help.