Blog 010: The Postal Service tried sending Mail by Cruise Missile.

As the name implies email does take inspiration in both form and function from traditional physical mail. The method of sending the data (mail) to increasingly higher order addresses before sending it to correspondingly lower addresses is taken from the physical method of sorting and distribution centers. Both can be used for the exchange of information between parties. Email is substantially faster for the vastly majority of use cases but is much slower than mailing physical data storage media when dealing with large amounts of information is to moved. 

Email functions substantially differently in practical terms than physical mail due to its electronic nature. Due to the massively simplified nature of sending mail electronically the ease of creating spam is accordingly simplified. This creates a need for sorting methods to filter out unwanted or harmful files, as well as default sorting categories for individual accounts not needed for physical mail. In the digital sphere this is usually done on the receiving side of the process, while the majority of the security screening for physical mail is done on the outbound side.* The most substantial difference for the majority of users is that physical mail, being physical, can allow for the transportation of goods and tangible objects rather than merely information.  Also people tend to have single mailing addresses and multiple email addresses.

*A little known fact is that the Postal Service has an armed component with arrest authority. Meanwhile Google can not shoot nor arrest people for misusing gmail. Yet.