Loren McDonald lists these 14 annoyance factors that drive email list churn:

1. Sending irrelevant email messages
2. Sending emails too frequently
3. Expanding permission to other mailings
4. Sending an offer to customers for a product/service they have already purchased
5. Not using any of the data you collected from recipients to create targeted messages
6. Lack of personalization
7. Bad personalization
8. Not using a friendly (recognizable) "From" name, especially in "welcome" messages
9. Using one “From” name/address in the welcome email and then different ones in your regular emails
10. Poor design or confusing navigation
11. Making it hard for readers to manage their subscriptions or contact you from email
12. Using one or two large images to show products or present information.
13. Using images to present action items
14. Emails with typos, the wrong date or product photo, broken links or coding errors.