H1

H2

H3

H4

H5

H6

Emphasis, aka italics, with asterisks or underscores.

Strong emphasis, aka bold, with asterisks or underscores.

Combined emphasis with asterisks and underscores.

Strikethrough uses two tildes. Scratch this.

Here’s a sentence with a footnote. ¹

• First item
• Second item
• Third item

1. First item
2. Second item
3. Third item

• Write the press release
• Update the website
• Contact the media

var s = "JavaScript syntax highlighting";
alert(s);

s = "Python syntax highlighting"
print s

No language indicated, so no syntax highlighting. 
But let's throw in a <b>tag</b>.

Blockquotes are very handy in email to emulate reply text. This line is part of the same quote.

Quote break.

This is a very long line that will still be quoted properly when it wraps. Oh boy let’s keep writing to make sure this is long enough to actually wrap for everyone. Oh, you can put Markdown into a blockquote.