Why is port 25 blocked?

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Tags

1. #thousands
2. #because
3. #writers
4. #default
5. #connections
6. #hijacked
7. #millions
8. #providers
9. #emails
10. #computer
11. #cable
12. #reason
13. #infected
14. #broadband
15. #block
16. #prevent
17. #restrict
18. #virus