Table of Contents

Preface; 1. Getting Started; 1.1 Downloading the Latest Release 1.2 Installing Sendmail; 1.3 Compiling Sendmail to Use LDAP 1.4 Adding the regex Map Type to Sendmail; 1.5 Compiling Sendmail with SASL Support; 1.6 Compiling Sendmail with STARTTLS Support 1.7 Compiling in STARTTLS File Paths; 1.8 Building a sendmail Configuration; 1.9 Testing a New Configuration; 1.10 Logging Sendmail; 2. Delivery and Forwarding; 2.1 Accepting Mail for Other Hosts; 2.2 Fixing the Alias0 Missing Map Error; 2.3 Reading Aliases via LDAP; 2.4 Configuring Red Hat 7.3 to Read Aliases from a NIS Server; 2.5 Configuring Solaris 8 to Read Aliases from a NIS Server; 2.6 Forwarding to an External Address 2.7 Creating Mailing Lists; 2.8 Migrating Ex-users to New Addresses; 2.9 Delivering Mail to a Program; 2.10 Using Program Names in Mailing Lists; 2.11 Allowing Non-login Users to Forward to Programs; 2.12 Fixing a .forward Loop; 2.13 Enabling the User Database; 3. Relaying; 3.1 Passing All Mail to a Relay 3.2 Passing Outbound Mail to a Relay; 3.3 Passing Local Mail to a Mail Hub; 3.4 Passing Apparently-Local Mail to a Relay; 3.5 Passing UUCP Mail to a Relay; 3.6 Relaying Mail for All Hosts in a Domain; 3.7 Relaying Mail for Individual Hosts; 3.8 Configuring Relaying on a Mail Exchanger; 3.9 Loading Class R via LDAP 3.10 Relaying Only Outbound Mail; 4. Masquerading 4.1 Adding Domains to All Sender Addresses; 4.2 Masquerading the Sender Hostname; 4.3 Eliminating Masquerading for the Local Mailer 4.4 Forcing Masquerading of Local Mail; 4.5 Masquerading Recipient Addresses; 4.6 Masquerading at the Relay Host; 4.7 Limiting Masquerading; 4.8 Masquerading All Hosts in a Domain; 4.9 Masquerading Most of the Hosts in a Domain; 4.10 Masquerading the Envelope Address; 4.11 Rewriting the From Address with the genericstable; 4.12 Rewriting Sender Addresses for an Entire Domain 4.13 Masquerading with LDAP; 4.14 Reading the genericstable via LDAP; 5. Routing Mail; 5.1 Routing Mail to Special Purpose Mailers; 5.2 Sending Error Messages from the mailertable; 5.3 Disabling MX Processing to Avoid Loops; 5.4 Routing Mail for Local Delivery; 5.5 Reading the mailertable via LDAP; 5.6 Routing Mail for Individual Virtual Hosts; 5.7 Routing Mail for Entire Virtual Domains; 5.8 Reading the virtusertable via LDAP; 5.9 Routing Mail with LDAP; 5.10 Using LDAP Routing with Masquerading 6. Controlling Spam 6.1 Blocking Spam with the access Database 6.2 Preventing Local Users from Replying to Spammers 6.3 Reading the access Database via LDAP; 6.4 Using a DNS Blackhole List Service; 6.5 Building Your Own DNS Blackhole List; 6.6 Whitelisting Blacklisted Sites; 6.7 Filtering Local Mail with procmail; 6.8 Filtering Outbound Mail with procmail; 6.9 Invoking Special Header Processing; 6.10 Using Regular Expressions in Sendmail; 6.11 Identifying Local Problem Users; 6.12 Using MILTER; 6.13 Bypassing spam checks; 6.14 Enabling spam checks on a per-user basis; 7. Authenticating with AUTH; 7.1 Offering AUTH Authentication; 7.2 Authenticating with AUTH; 7.3 Storing AUTH Credentials in the authinfo File; 7.4 Limiting Advertised Authentication Mechanisms; 7.5 Using AUTH to Permit Relaying 7.6 Controlling the AUTH= Parameter; 7.7 Avoiding Double Encryption; 7.8 Requiring Authentication; 7.9 Selectively Requiring Authentication; 8. Securing the Mail Transport 8.1 Building a Private Certificate Authority; 8.2 Creating a Certificate Request; 8.3 Signing a Certificate Request; 8.4 Configuring Sendmail for STARTTLS; 8.5 Relaying Based on the CA 8.6 Relaying Based on the Certificate Subject; 8.7 Requiring Outbound Encryption; 8.8 Requiring Inbound Encryption; 8.9 Requiring a Verified Certificate; 8.10 Requiring TLS For a Recipient; 8.11 Refusing STARTTLS Service; 8.12 Selectively Advertising STARTTLS; 8.13 Requesting Client Certificates; 9. Managing the Queue 9.1 Creating Multiple Queues; 9.2 Using qf, df and xf Subdirectories; 9.3 Defining Queue Groups; 9.4 Assigning Recipients to Specific Queues; 9.5 Using Persistent Queue Runners 9.6 Using a Queue Server; 9.7 Setting Protocol Timers 10. Securing Sendmail; 10.1 Limiting the Number of Sendmail Servers; 10.3 Updating to Close Security Holes; 10.4 Patching to Close Security Holes; 10.5 Disabling Delivery to Programs 10.6 Controlling Delivery to Programs; 10.7 Disabling Delivery to Files; 10.8 Bypassing User .forward Files; 10.9 Controlling Delivery to Files; 10.10 Running Sendmail Non-set-user-ID root 10.11 Setting a Safe Default Userid; 10.12 Defining Trusted Users 10.13 Identifying the Sendmail Administrator; 10.14 Limiting the SMTP Command Set; 10.15 Requiring a Valid HELO; 10.16 Restricting Command-line Options; 10.17 Denying DoS Attacks; Index

About the Author

Craig Hunt has worked with computer systems for the last twenty years, including a stint with the federal government as both a programmer and systems programmer. He joined Honeywell to work on the WWMCCS network in the days before TCP/IP, back when the network used NCP. After Honeywell, Craig went to work for the National Institute of Standards and Technology. He's still there today and is currently the leader of the Network Engineering Group. Craig is the author of TCP/IP Network Administration and other O'Reilly books.

Reviews

"If you are looking for a companion to a mission-critical sendmail instal, the 'other' bat book is the one for you. If you want to be able to set up and do a few cool things with your own mailserver, this is all you will need. It's written by Craig Hunt too, so you know it's going to be easy to read and accurate." - Nick Veitch, Linux Format, July