There are lots and lots of pages on Active Rain about uploading photos, and the instructions are very easy. I've been doing it ever since they added the feature to the site last year.
So why was I having trouble uploading photos yesterday? I thought perhaps their "photo server" was down, and just blogged about other things than architecture.
Today I figured it out - really by trial and error. Unless the instructions have changed, I don't remember seeing anything about file size. One great thing about uploading to Active Rain is that you can set the size in the popup box to shrink the size of the photo ... but that step comes AFTER the photo has been uploaded.
My camera is a few years old, so it's probably a 6 MB rather than a 10 MB or 12 MB that you have today. Nonetheless, the typical photo is about 3 MB - which I can e-mail to anyone with a professional e-mail host, but which is JUST TOO BIG to upload to Active Rain. The server times out.
So, resize your photos BEFORE you try to upload them to Active Rain.

Hey Sharon,
I learned that the hard way too. Took me a couple hours to figure it out a few months ago.
Sean Allen
Hey Sharon,
I learned that the hard way too. Took me a couple hours to figure it out a few months ago.
Sean Allen
Sharon,
I've never thought about it :)
I've resized all my photos for blogging and never experienced that problem, but initially i was more afraid of my photos being used for commercial reasons (since I sell my images for that purpose), that I've made them all small for blogging reasons :)