size of e-mail / clean-up of e-mail

I was wondering how thunderbird 'knows' the size of an e-mail. This information is not available in Gmail .. is this available, somewhere ?

Is it possible to export all the e-mail messages, their date, and their size ? THe intent would be to build a 'dashboard', to help people do their cleanup .. similarly to treemaps
 
happy I’m fine ..and truly thankful
Inappropriate?
1 person has this question

User_default_medium