group by sender, date, year, subject etc...
View mails stored in indexedDB
View Mails
key value interface with optional checksum
compute count/sum/avg...
map creation from character pairs
compute digest(Node.js / Web Cryptography API)
bytes(ArrayBuffer/DataView/Buffer) -> string
uuid(ArrayBuffer/DataView/Buffer) -> String
buffer(ArrayBuffer/Dataview) -> key value pair -> Map(key, value list)