Over years of delivering millions of emails, we've come across some email patterns that work and many that don't. Some are design related while some are organisation related. Let's break some bubbles here - in no particular order.

1. Remember, you are designing an email, not a website. If you want fine-grain controls like 'line heights', you are at the wrong place.

2. The more you nitpick on the design, the more likely it will break in email clients. (i.e. more moving parts == more breakages).

3. Transactional emails are best delivered in plain text.

4. For best results, HTML emails (transactional and marketing) must (mostly) fit 'above the fold'.

5. Rethink your design if it is more than one scroll depth.

6. The combined time spent by all the recipients who opened your marketing email will be lesser than the time you spent designing it. (This statement is an exaggeration, but you get the drift.)

7. Emails are being designed to impress bosses, not the end readers.

8. Avoiding spam folders is largely a function of the content of your email. Technology or the pedigree of your email sending service cannot help you if your content is unsolicited.

9. The top three email service providers control ~80% of the market. They can break you.