I've never had any problems with imgur and the storage capacity seems to have no limits.
First things first...a note about downloading images from emails, sstv's, etc. I always save them to desktop first. This allows for easier (in my opinion) access by imgur to locate a file. After I'm done posting the image, then I go back and move the file to it's respective folder.
So you've logged in to your imgur account (It's Free!) and it looks like this:
Click on the "Add images" (See the red arrow), and then it looks like this next:
Click on "Browse" (See the red arrow) and navigate to "Desktop", and then it looks like this next:
Click on "Desktop" (See the red arrow) and select the item you want to add to imgur. Then it will look like this next:
Click on the added image (See the red arrow) and then it will look like this next:
Click on "Linked BBCode" (See the red arrow) and then your image is ready to paste in a posting or chat room.
A note on the size of the pasted image: Before you select "Add Image", click on the drop down box in imgur that looks like this:
Click on the option for "640x480(message boards)". This seems to fit well on the HFU posts.
I hope this is of some help!