XBee Pro S3B serial buffer memory in transparent mode

I am wondering if the XBee Pro S3B modules have any storage memory for the serial buffer that isn’t volatile when operating in transparent mode. Essentially, if I want to send data from one module to another in transparent mode, and if for some reason it can’t make the connection with the other module, can I put the module that is trying to send the data in sleep mode and just have it try to send the same data later? Is the data that enters the serial buffer for transmission stored in non-volatile memory, or is that data lost from the serial buffer once the module enters sleep mode?

No, it does not offer that kind of option.