There is no unsend

You cannot ‘unsend’ an email. That is the big problem. Mixing up the contents of the Cc-header and the Bcc-header can result in having made enemies forever. With some email clients you can postpone the actual sending of emails. This queuing can be very handy. The queued emails can be checked later, when you are less emotional for instance.

Formatting of your message

Avoid sending styled text as much as possible.

So no accents, diacritics, ligatures etc. Sending styled text (rtf or even more proprietary) is against the philosophy of the internet. Even sending html files (web pages) should be avoided whenever possible.

ASCII

The crucial communication rule on the internet is:

So do not use styled text with varying font size, italic, bold and colored fonts, and try to avoid sending attachments.

Many email clients allow the user to add formatting to their text. Popular formatting standards are html and rtf.

ASCII styling

Even with plain ASCII there is still a lot you can do to structure your emails.

You can use uppercase and lowercase. Do not use uppercase in the middle of a sentence to indicate emphasized text: it will give the impression you are shouting. “You have to do this before MONDAY” is insulting. Be creative, like “You have to do this before *Monday*”.

Underline text like this: “_This is very important_”.

You can use strings of asterisks “*” as text separators. Software developers have to stick to plain ASCII when writing computer code. They are very creative in using all kinds of ASCII characters to have text comments stand out, like:

Rtf

In principle, the idea behind Microsoft's rtf (Rich text format) is appealing: a general cross-platform encoded 7-bit ASCII. The problem is that Microsoft is continuously changing its proprietary rtf-standard, making it very difficult for independent software vendors to develop software with backward compatibility. In addition rtf-files tend to be bulky. You need a viewer (which many email clients have) to be able to read the formatted text