So I trudged to Michaels. I actually found a possible solution located high up on a shelf that looked big enough for even those oversized cards. I couldn't find any at eye level, and, as usual, there was no worker in sight to help me. So with two toddlers in tow, I decided to scale the wall to get them down. They looked perfect, but had no price tag, so I took them up to the register to ask. She rang them up at 8.99 each and then as I proceeded to check out, I was told my 40% off coupon didn't work because they were already on sale. So, I naturally inquired, "how much are they regularly (in case I needed more in the future)?" She didn't know and was about to go find out elsewhere. Again, with two toddlers in tow, I told her not to worry about it. Have I mentioned how much I dislike Michaels?
I got them home and was able to file all of my cards received separated by sender with the included dividers Love it! Now getting cards might even be as much fun as sending them-now that I have a place to immediately put them, rather than debating whether or not they are worthy of being saved!