The content of the letter isn't much; just a few words stating that they know Caiyi's whereabouts. If Di Kuohai wants to know, he should come to meet at Heavenly Snake Reef.
Lastly, it added that due to travel reasons, they would wait for Di Kuohai at Heavenly Snake Reef for a maximum of two hours, no more.
That probably explains why Ye Zhen will regret it for a lifetime.
Honestly, this letter was quite abrupt for Ye Zhen to receive.
After the initial ecstasy and anxiety, Ye Zhen had completely calmed down by now.
Regarding Caiyi, Ye Zhen has only told Six Directions: one being Yun Ben, and the other being the Five Immortals Hall. Ye Zhen used this matter as a condition for their invitations.
As long as they can help him find Caiyi's whereabouts, Ye Zhen would join the respective hall, even without any compensation.
