Add 'Aliases' to E-Mail preferences

[humdinger]

This is hrev57217, 64bit.

Many email providers allow having aliases, we should be able to configure mail_daemon to use them and Mail to choose the alias from which to send a mail.

The E-Mail prefs' Account settings could show an 'Aliases' popup menu. Mockup:

It contains by default a <no aliases> item, plus an Add alias and a Remove current alias.

Below you enter the alias's Real name and Return address

Clicking Add alias opens a modal window to enter the alias name.

Clicking Apply saves the alias with its "Real name" and "Return address".

Once you have aliases configured, they appear with the chosen name and return address in Mail's "From" popup:

Of course, that's just the GUI part...

[humdinger]

E-Mail prefs mockup

[humdinger]

The Mail window for illustration

[nephele]

on the left side below incoming outgoing and email filters there should be a new tab called addresses in which you can configure this imo. Likely just as a list in which you can append adressed you want, with the option to overide the real name if needed.

[nephele]

The From header should also be editable as text, with a seperate account popup to the right of it, so this can be used ad-hoc.