Exim Internet Mailer

Exim's interfaces to mail filtering

Copyright © 2026 The Exim Maintainers
Revision 4.100-RC2 - 04 Aug 2026

• 1. Forwarding and filtering in Exim
  • 1. Introduction
  • 2. Filter operation
  • 3. Testing a new filter file
  • 4. Installing a filter file
  • 5. Testing an installed filter file
  • 6. Details of filtering commands
• 2. Sieve filter files
  • 1. Recognition of Sieve filters
  • 2. Saving to specified folders
  • 3. Strings containing header names
  • 4. Exists test with empty list of headers
  • 5. Header test with invalid MIME encoding in header
  • 6. Address test for multiple addresses per header
  • 7. Semantics of keep
  • 8. Semantics of fileinto
  • 9. Semantics of redirect
  • 10. String arguments
  • 11. Number units
  • 12. RFC compliance
• 3. Exim filter files
  • 1. Format of Exim filter files
  • 2. Data values in filter commands
  • 3. String expansion
  • 4. Some useful general variables
  • 5. Header variables
  • 6. User variables
  • 7. Current directory
  • 8. Significant deliveries
  • 9. Filter commands
  • 10. The add command
  • 11. The deliver command
  • 12. The save command
  • 13. The pipe command
  • 14. Mail commands
  • 15. Logging commands
  • 16. The finish command
  • 17. The testprint command
  • 18. The fail command
  • 19. The freeze command
  • 20. The headers command
  • 21. Obeying commands conditionally
  • 22. String testing conditions
  • 23. Numeric testing conditions
  • 24. Testing for significant deliveries
  • 25. Testing for error messages
  • 26. Testing a list of addresses
  • 27. Testing for personal mail
  • 28. Alias addresses for the personal condition
  • 29. Details of the personal condition
  • 30. Testing delivery status
  • 31. Multiple personal mailboxes
  • 32. Ignoring delivery errors
  • 33. Examples of Exim filter commands