| Category | Description |
| -d0 | Display system configuration information |
| -d1 | Show sender information |
| -d2 | Trace sendmail 's exit information |
| -d3 | Print the load average |
| -d4 | Trace disk-space calculations |
| -d5 | Trace timed events |
| -d6 | Show failed mail |
| -d7 | Trace the queue filename |
| -d8 | Trace hostname canonicalization |
| -d9 | Trace identd exchanges |
| -d10 | Trace recipient delivery |
| -d11 | Trace delivery generally |
| -d12 | Trace mapping of relative host |
| -d13 | Trace the envelope and envelope splitting |
| -d14 | Show header field commas |
| -d15 | Trace incoming connections |
| -d16 | Trace outgoing connections |
| -d17 | Trace MX record lookups |
| -d18 | Trace SMTP replies |
| -d19 | Show ESMTP MAIL and RCPT parameters |
| -d20 | Show delivery agent selection |
| -d21 | Trace rules and rule sets |
| -d22 | Show address tokenization |
| -d23 | Unused |
| -d24 | Trace assembly of address tokens |
| -d25 | Trace the send-to list |
| -d26 | Trace recipient queueing |
| -d27 | Trace aliasing, ~/.forward file handling, and controlling user |
| -d28 | Trace the User Database |
| -d29 | Trace localaddr rule set rewrite of local recipient |
| -d30 | Trace header processing |
| -d31 | Trace header validation |
| -d32 | Show collected headers |
| -d33 | Watch crackaddr ( ) |
| -d34 | Trace header generation and skipping |
| -d35 | Trace macro definition and expansion |
| -d36 | Trace the internal symbol table |
| -d37 | Trace setting of options and classes |
| -d38 | Trace database processing |
| -d39 | Display digit database mapping |
| -d40 | Trace processing of the queue |
| -d41 | Trace queue ordering |
| -d42 | Trace connection caching |
| -d43 | Trace MIME conversions |
| -d44 | Trace safefile ( ) |
| -d45 | Trace envelope sender |
| -d46 | Show xf file's descriptors |
| -d47 | Trace effective/real user/ group IDs |
| -d48 | Trace calls to the check_ rule sets |
| -d49 | Trace checkcompat ( ) |
| -d50 | Trace envelope dropping |
| -d51 | Trace unlocking and prevent unlink of xf file |
| -d52 | Trace controlling TTY |
| -d53 | Trace xclose ( ) |
| -d54 | Show error return and output message |
| -d55 | Trace file locking |
| -d56 | Trace persistent host status |
| -d57 | Monitor vsnprintf ( ) overflows |
| -d58 | Trace buffered file system I/O |
| -d59 | Trace XLA from contrib |
| -d60 | Trace database map lookups inside rewrite ( ) |
| -d61 | Trace gethostbyname ( ) |
| -d62 | Log file descriptors before and after all deliveries |
| -d63 | Trace queue processing forks |
| -d64 | Trace MILTER interactions |
| -d65 | Trace nonallowed user actions |
| -d66 | Unused |
| -d67 | Unused |
| -d68 | Unused |
| -d69 | Unused |
| -d70 | Unused |
| -d71 | Unused |
| -d72 | Unused |
| -d73 | Unused |
| -d74 | Unused |
| -d75 | Unused |
| -d76 | Unused |
| -d77 | Unused |
| -d78 | Unused |
| -d79 | Unused |
| -d80 | Trace Content-Length: header (Sun version) |
| -d81 | Trace > option for remote mode (Sun version) |
| -d82 | Unused |
| -d83 | Unused |
| -d84 | Unused |
| -d85 | Unused |
| -d86 | Unused |
| -d87 | Unused |
| -d88 | Unused |
| -d89 | Unused |
| -d90 | Unused |
| -d91 | Log caching and uncaching connections |
| -d92 | Unused |
| -d93 | Unused |
| -d94 | Force RSET failure |
| -d95 | Trace AUTH= authentication |
| -d96 | Allow SSL_CTX_set_info_callback ( ) call |
| -d97 | Trace setting of auto mode for I/O |
| -d98 | Trace timers (commented out in the code) |
| -d99 | Prevent backgrounding the daemon |
