The Exim SMTP Mail Server
Official Guide for Release 4
by Philip Hazel
New second edition.

Changes from the previous edition of this book

This second edition of "The Exim SMTP Mail Server: Official Guide to Release 4" covers Exim up to release 4.66.

One of the main reasons for revising this book was the inclusion of content-scanning facilities in Exim from release 4.50 onwards. Chapters 14 and 15 (Message reception and policy controls and Rewriting addresses) in the previous edition have been replaced by five chapters covering:

• Message reception.
• Access control lists.
• Address verification.
• Scanning incoming messages.
• Address and header processing.

The remainder of the book has been revised to correct errors and update it for other additions to Exim, and to revise some of the general comments in the light of changing circumstances and current practice.

The previous edition contained a number of summary lists of options for routers and transports. As the book does not cover the more rarely used options, these were never complete, and became even more out-of-date as new options were added, so they are no longer present in this edition. The reference manual is the place to look for complete lists of options. Despite the removal of these lists, the body of the book is 6.5% larger than it was before.

The second appendix, which covered the regular expressions that are supported by the PCRE library, has been removed from this edition, both in the interest of reducing the book's length, and also because PCRE is now standardly installed on a number of systems and its current documentation is therefore widely available.