In the past, I've explained how to write a convincing email,  how to write a killer sales email, and how to get people to open and read your emails.  

While researching those columns, I collected these statistics which expose how insanely pervasive email has become in the workplace:

1. Number of email accounts worldwide: 4.6 billion
2. Number of email users worldwide: 2.7 billion
3. Number of business emails sent/received daily: 212 billion
4. Average business emails sent/received per day per person: 131
5. Percentage of email traffic that is actually SPAM: 45%
6. Percentage of SPAM that actually gets delivered: 9%
7. Percentage of B2B emails that contain marketing messages: 54%
8. Percentage of consumers who check their email daily: 91%
9. Percentage of consumers who made a purchase due to an email: 66%
10. Average click-through rate of B2B marketing emails: 1.7%
11. Percentage of email opens that occur with two days of sending: 76%
12. Percentage of emails opened on mobile devices: 48%
13. Percentage of emails opened on iPhones: 25%
14. Average hours per week people spend checking for new emails: 30
15. Percentage of people who check email while on the phone: 43%
16. Percentage of people who check email while watching TV: 70%
17. Percentage of people who check email during meetings: 51%
18. Percentage of people who check email while in bed: 60%
19. Percentage of people who check email while on vacation: 50%
20. Percentage of people who check email when using the toilet: 42%
21. Percentage of people who check email while driving: 18%

Sources: Adobe, MovableInk, Howard University, USC, The Radacati Group, SpamLaws.com, Bloomberg, Convince&Convert, ExactTarget & Hubspot.