Overview

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This chapter covers the following:

• First, we'll show how to verify that the qmail processes that should be running are actually running.

• Next, we'll describe how to locate and interpret the log files created by qmail and the support processes.

• Then, we'll also describe how to read message headers and extract diagnostic information from them.

• Next, we'll directly test the qmail SMTP service.

• Finally, we'll look at several typical problem scenarios and provide step-by-step procedures for identifying their causes.

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