Did Cao Cao, a former Battle of Red Cliffs, write a letter to Sun Quan?

According to historical records, before Battle of Red Cliffs, Cao Cao wrote a letter to Sun Quan. The original text of the letter is like this: "The sin of the nearest person's words must refer to the south, and Liu Cong will give up." Today, there are 800 water conservancy troops, and Fang and the generals will hunt in Wu. ".It was because of this letter that Sun Quan felt further threatened, which finally contributed to Sun Liulian's resistance to Cao.

But why did Cao Cao write such a letter to Sun Quan at this time? So some historians think that Cao Cao never wrote this letter, while others think that Cao Cao wrote a threatening letter or a challenge letter. In my humble opinion, this will not be a threatening letter, let alone a challenge letter, because Cao Cao is unlikely to provoke Sun Quan at this time, so it should be an invitation letter or cooperation letter with a slight threat. He first talked about the expedition, and then told Sun Quan that he now has as many as 800,000 water troops. On the one hand, he wants to tell Sun Quan that I am strong, so don't help others deal with me. On the other hand, he said that you would never refuse to cooperate with me because I have such strong strength. And what does he want to cooperate with Sun Quan? That is, "I will hunt in Wu" I don't think Cao Cao wants to tell Sun Quan that I want to hunt in your territory and provoke Sun Quan, but he wants to invite Sun Quan to hunt together, and the prey is Liu Bei who is desperate. This "Wu dialect" is not necessarily in the territory of Dongwu, but can also be understood as being at the gate of Dongwu, because Liu Bei is at Xiakou at this time, and Xiakou is near Wu and far from Wei, so this word is used. Moreover, if Liu Bei is defeated again, he is likely to flee into the territory of Wu. If Cao Cao rashly led the troops in pursuit, it would be inappropriate, so he would inform Sun Quan in advance and show his strength and invite Sun Quan to hunt together. Because Sun Quan and Liu Bei are not related by blood, but by marriage, Cao Cao is sure to win this battle. But perhaps Sun Quan misinterpreted Cao Cao's meaning, or thought that Cao Cao would be difficult to protect himself if he got Jingzhou, so he finally decided to unite Liu against Cao Cao.