The question [*Save icon, is the floppy disk icon dead?*](https://ux.stackexchange.com/questions/3117/save-icon-is-the-floppy-disk-icon-dead) made me think about another icon. 

[![Mail icon](https://i.stack.imgur.com/3q9ODs.jpg)](https://i.stack.imgur.com/3q9ODs.jpg)

As the number of mailed letters drops from year to year, I wondered if the icon just can't be associated with the letter anymore. Of course this will yet take some time, but just as the floppy disk it will be unknown to the youngster in the (near?) future. 

Just as the floppy disk question - does the envelope icon become obsolete someday? Can and should it be replaced with something more modern and if so what?

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Everything beneath this line is IMHO.

The floppy disk is a control element like set in stone. It was, is and will be there to save. 

The envelope however isn't really mandatory. You can replace it with a paper plane, a pen (for "write mail") or stamp. Fastmail for example although having the envelope in the logo, doesn't use it a single time in their Web UI. 

Why should we even care about this? Maybe we can (and therefore should) already switch (like the paper plane?).