Thunderbird: How to reference a mail permanently with WebExtensions

Hi all,

do I have a chance to find a specific mail when I know the exact time? My problem is that browser.messages.query() only has fields for before(some time stamp) and after(some time stamp), but not at(some time stamp). What do I need to remember/store from a specific mail to find it again later on? Can I search for an message id?

Regards, Michael