Why are some of the mail bag icons red and why are some yellow? Just curious.
The red ones are old PT and the yellow ones are new PT. We've had a refurbishing lately.
I think it has more to do with the number of posts in them. Look! The red ones are bulging!! Consider the colour coding a stress indicator - the "paper" of the red ones are stretched to the limit!
The red ones are the ones that have a large number of posts, these are the ones which are popular and have been going on for a long time.
The yellow ones are the ones which have fewer number of posts thus generally symbolising the newly created threads.