| FEATURE( ) | § | Description |
| accept_unqualified_senders | FEATURE(accept_unqualified_senders) | Allow unqualified MAIL FROM: |
| accept_unresolvable_domains | FEATURE(accept_unresolvable_domains) | Accept unresolvable domains |
| access_db | Section 7.5 | A database for mail policy |
| allmasquerade | FEATURE(allmasquerade) | Masquerade recipient as well as sender |
| always_add_domain | FEATURE(always_add_domain) | Add the local domain even on local mail |
| authinfo | FEATURE(authinfo) | Use a separate database for authentication information |
| bestmx_is_local | FEATURE(bestmx_is_local) | Accept best MX record as local if in $=w |
| bitdomain | FEATURE(bitdomain) | Convert BITNET addresses into Internet addresses (deprecated) |
| blacklist_recipients | Section 7.5.5 | Look up recipients in access database |
| compat_check | FEATURE(compat_check) | Screen sender/recipient pairs |
| delay_checks | Section 7.5.6 | Check SMTP RCPT TO: first |
| dnsbl | Section 7.2 | Reject based on various DNS blacklists |
| domaintable | FEATURE(domaintable) | Rewrite old domain as equivalent to new domain |
| enhdnsbl | Section 7.2.2 | Enhanced dnsbl lookups |
| generics_entire_domain | FEATURE(generics_entire_domain) | Match subdomains in generics table |
| genericstable | FEATURE(genericstable) | Transform sender addresses |
| ldap_routing | ldap (was ldapx) | Reroute recipients based on LDAP lookups |
| limited_masquerade | FEATURE(limited_masquerade) | Only masquerade MASQUERADE_DOMAIN hosts |
| local_lmtp | FEATURE(local_lmtp) | Deliver locally with LMTP and mail.local |
| local_no_masquerade | FEATURE(local_no_masquerade) | Don't masquerade local mail |
| local_procmail | FEATURE(local_procmail) | Use procmail (1), etc. as local delivery agent |
| lookupdotdomain | FEATURE(lookupdotdomain) | Enable .domain secondary access.db lookups |
| loose_relay_check | Section 7.4.2 | Allow %-hack relaying |
| mailertable | FEATURE(mailertable) | Database selects new delivery agents |
| masquerade_entire_domain | FEATURE(masquerade_entire_domain) | Masquerade all hosts under a domain |
| masquerade_envelope | FEATURE(masquerade_envelope) | Masquerade the envelope as well as headers |
| msp | FEATURE(msp) | Create a mail submission cf file |
| nocanonify | FEATURE(nocanonify) | Don't canonify with $[ and $] |
| nodns | FEATURE(nodns) | Omit DNS support from configuration file (deprecated) |
| no_default_msa | FEATURE(no_default_msa) | Disable automatic listening on MSA port 587 |
| notsticky | FEATURE(notsticky) | Don't differ unqualified versus qualified addresses |
| nouucp | FEATURE(nouucp) | Eliminate all UUCP support |
| nullclient | FEATURE(nullclient) | Relay all mail through a mail host |
| preserve_local_plus_detail | FEATURE(preserve_local_plus_detail) | Retain plussed addresses for delivery |
| preserve_luser_host | FEATURE(preserve_luser_host) | Preserve recipient host with LUSER_RELAY |
| promiscuous_relay | Section 7.4.3 | Allow unbridled relaying |
| queuegroup | FEATURE(queuegroup) | Select queue groups via the access database |
| rbl | FEATURE(rbl) | Reject connections based on rbl.maps.vix.com (V8.9 through V8.11) |
| redirect | FEATURE(redirect) | Add support for address.REDIRECT aliases |
| relay_based_on_MX | Section 7.4.4 | Relay based on MX records |
| relay_entire_domain | Section 7.4.5 | Relay based on $=m in addition to $=w |
| relay_hosts_only | Section 7.4.6 | Relay individual hosts, not domains |
| relay_local_from | Section 7.4.7 | Relay based on $=w and MAIL FROM: |
| relay_mail_from | Section 7.4.8 | Relay based on MAIL FROM: and RELAY in access_db |
| smrsh | Section 5.8.2 | Use smrsh (sendmail restricted shell) |
| stickyhost | FEATURE(stickyhost) | Differ unqualified from qualified addresses |
| use_ct_file | FEATURE(use_ct_file) | Use /etc/mail/trusted-users for trusted users |
| use_cw_file | FEATURE(use_cw_file) | Use /etc/mail/local-host- names for local hosts |
| uucpdomain | FEATURE(uucpdomain) | Convert UUCP hosts via a database (deprecated) |
| virtuser_entire_domain | FEATURE(virtuser_entire_domain) | Match subdomains in the virtual user table |
| virtusertable | FEATURE(virtusertable) | Support for virtual domains |
