| S and R | Address rewrite rules |
|   | RLHS RHS |
|   | S13 |
|   | R$* < $* > $* <@> |
| ---------- | --------------------------------------------- |
| D | Define macro |
|   | Dmacro name string |
|   | Dn MAILER_DAEMON |
| ---------- | --------------------------------------------- |
| C and F | Define classes |
|   | Cclass name string string ... |
|   | CE root |
|   | FR-o /etc/mail/relay-domains |
| ---------- | --------------------------------------------- |
| M | Define mailer |
|   | Mmailer field=value.field=value ... |
|   | Mprocmail |
| ---------- | --------------------------------------------- |
| H | Define header |
|   | H[?flags?]header name header template |
|   | H?P?Return-Path: <$g> |
| ---------- | --------------------------------------------- |
| O | Set Option |
|   | Ooption-name = value |
|   | O SevenBitInput=false |
| ---------- | --------------------------------------------- |
| P | Precedence definitions |
|   | Pfield name = value |
|   | Pfirst-class=0 |
| ---------- | --------------------------------------------- |
| V | Configuration version level |
|   | Vversion |
|   | V8/Berkeley |
| ---------- | --------------------------------------------- |
| K | Key file definition |
|   | Kmap mapclass arguments |
|   | Kvirtuser hash -o /etc/mail/virtusertable |