quality posts: 18
These are absolutely worthless when the envelope size isn't there. I cannot imagine what standard size ANYTHING would fit these except maybe an 8.5x11 folded lengthwise??? By the size of the box it's a guess that max measurements for the envelopes are around 6x11? BUT if the envelopes are multiply stacked...it could be anything smaller in multiple stacks (which is probably the case).
That light at the end of the tunnel? It's a train.