| discard | The discard delivery agent accepts then discards email messages (V8.9 and later). |
| /= (forward slash) | The /= delivery-agent equate defines a chroot (8) directory (V8.10 and later). |
| See this section | Delivery can now be made to Unix domain sockets (V8.10 and later). |
| See this section | It is now possible to delete from, add to, and modify delivery-agent flags using the MODIFY_MAILER_FLAGS mc command (V8.10 and later). |
| m= | The m= delivery-agent equate limits the number of envelopes that can be delivered during any single SMTP or LMTP connection (V8.10 and later). |
| P= | P=[TCP] is fully deprecated as of V8.10, and disallowed as of V8.12. |
| Q= | The Q= delivery-agent equate specifies which queue group to use (V8.12 and later). |
| r= | The r= delivery-agent equate limits the number of recipients allowed per envelope (V8.12 and later). |
| W= | The W= delivery-agent equate sets the timeout for a delivery agent to complete delivery (V8.10 and later). |
| F=% | The F=% delivery-agent flag specifies that delivery should be held until an ETRN command or a -q [IRS] run (V8.10 and later). |
| F=1 (one) | The F=1 delivery-agent flag specifies that null bytes should be removed from headers (V8.10 and later). |
| F=2 | The F=2 delivery-agent flag forces SMTP even if ESMTP is offered (V8.12 and later). |
| F=6 | The F=6 delivery-agent flag requires the high bit to always be stripped from headers (V8.10 and later). |
| F=z | The F=z delivery-agent flag requires delivery to use the LMTP protocol (V8.9 and later). |
| F=Z | The F=Z delivery-agent flag causes sendmail to honor the DialDelay option and allow a second connection attempt following an initial connection failure (V8.12 and later). |