Is email "old school"? Sure―and it's still with us because it works wonders. Social media may get more press, but email marketing campaigns reach and engage billions of people worldwide every year.

Email has many advantages. It goes direct to a customer's digital doorstep. It can be personalized, not just sent to a generic user base. And it's so much cheaper than many other marketing tactics. If you're a small business, email can be your best friend.

Smart businesses use email marketing tactics as an integral part of their workflows, even when they use other approaches. Email marketing technology is used by 82% of companies, according to a report by marketing research firm Ascend2. Professional marketers depend on email marketing more than any other practice.

Whatever the size of your business, here are 10 email marketing best practices that will help you make the most of your campaigns.

1. get personal
2. connect the subject line to the first line
3. time it right
4. keep it short and sweet
5. be clear and conversational
6. ask questions
7. remember mobile users
8. try a/b testing
9. measure, tweak, repeat
10. make sharing easy