I want to pre-approval guests but i can't find the conversation in an inbox

[Jazila0]

guest send email to an alternative email id in my airbnb account, now I can't find conversation in my airbnb inbox   hence i fail to pre-approval,

please let me know how to go about so i can pre approval

[Alice-and-Jeff0]

IF there is not a booking, they do not have an email address to send you any email outside the system.