Sendmail Cookbook by Hunt, Craig -- Read -- Imperial Library of Trantor

Index

sendmail Cookbook Dedication Preface

Introduction Using This Cookbook Audience Organization Software Versions Conventions We’d Like to Hear from You Acknowledgments

1. Getting Started

Introduction 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

Introduction 2.1. Accepting Mail for Other Hosts 2.2. Fixing the Alias0 Missing Map Error and Creating Simple Aliases 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 Nonlogin Users to Forward to Programs 2.12. Fixing a .forward Loop 2.13. Enabling the User Database

3. Relaying

Introduction 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

Introduction 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

Introduction 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

Introduction 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

Introduction 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

Introduction 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

Introduction 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

Introduction 10.1. Limiting the Number of sendmail Servers 10.2. Limiting the Number of Network Accessible 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 User ID 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

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