My photos come up in MS Office Picture Manager. If you click on the Edit function, there will be a menu come up on the right side. Choose "Resize" and then choose "Predefined width x height". You can pick e-mail large or small and then hit "Okay"
Now save the file in a convenient place with a name other than the original file. When you use this forum to attach a file, just browse for it and select. Hit upload and you are there.
There are a couple of other ways to do it, but it mostly works the same way. You have to get into the edit function of whatever software you are using and go from there.
I'll require a large iced tea during my tour.........