[oscillator]

I write all my work e-mail in GNU Emacs and use the Emacs VM mailer.

Because it's all inside Emacs, text from other contexts -- code, shells, mailboxes, and compiler and tool output -- can be accurately and quickly pulled into the messages you compose, improving the content and reliability of what you're saying in mail.

For example, if I want to use a complex identifier from a source file I've just looked at, I can autocomplete it (M-. or find-tag) quickly from a substring. I can choose autocompletion suggestions simultaneously from all contexts.

Obviously, copying and pasting regions from those other contexts is much more immediate too.

This is in addition to the advantages of having a familiar and powerful editing tool for formatting, tidying up messages, trimming unnecessary content, etc.

I could, but wouldn't want to, live without it.