We should stick stamps on emails just because it's cute.
Do we need more stamps when the attachments are larger? And/or is it more about the distance (hops) of travel?

@bleeptrack How about both, a higher fee for the megabytes plus the airmail extra counterpart for avian carrier?

https://www.rfc-editor.org/rfc/rfc2549.html

https://en.wikipedia.org/wiki/Airmail_stamp

RFC 2549: IP over Avian Carriers with Quality of Service