| Section 25.4.1 | The ability to include headers based on sendmail macros was added (V8.10 and later). |
| Section 25.5 | Headers can now be screened by using rule sets (V8.9 and later). |
| Section 25.6.3 | The H_BINDLATE header flag was added (V8.10 and later). |
| Section 25.6.16 | The H_STRIPCOMM header flag was added (V8.10 and later). |
| Section 25.6.18 | The H_USER header flag was added (V8.11 and later). |
| Auto-Submitted: | The auto-generated phrase used by vacation was changed to auto-replied for the Auto-Submitted : header (V8.12 and later). |
| Received: | V8.9, V8.10, V8.11, and V8.12 each added additional information to the Received : header. |