What steps will reproduce the problem?
1. Send a post that is larger than 2 wow paragraphs (255 characters)
2. Watch it sometimes appear as A C B rather than A B C
3. More frequently appear when talking across B.tag than Whisper.

What is the expected output? What do you see instead?

Expected output is reading it A B C rather than A C B because WoW side spam protection re-arranging the hierarchy of the post. Deeming that C came before B although it is the reverse.

What version of the product are you using?
3.7.5 but I have a high suspicion that It does not exist in the newer version Either.

Do you have an error log of what happened?
Doesn't come out as an Error...

Please provide any additional information below.

I reckon a simple Fix would be applying a Delay rule to each post. So if you type Five WoW paragraphs, you can either through options or manipulate the code directly and set a Ms difference between each post. So A-> 50ms -> B-> 50ms -> C etcetra. And during this action, perhaps add a Loading screen to indicate that the player shouldn't close the whisper window or similar.

I reckon this is one way to circumvent future issues of spam protection and by allowing the users themselves to perhaps manipulate it, they can change the Ms till it works if they experience problems with the current set-up due changes on WoW server side.