[SYMBOL] [A] [B] [C] [D] [E] [F] [G] [H] [I] [J] [K] [L] [M] [N] [O] [P] [Q] [R] [S] [T] [U] [V] [W] [X] [Z] n class  n delivery agent flag  N line (qf file)  N= delivery agent equate  N= queue-group equate  name servers  2nd  name-server lookups  NAMED_BIND compile-time macro  names     alternative for sendmail      canonical  2nd  3rd      canonicalizing  [See canonicalization]     of classes      controlling terminal      DNS  [See DNS]     domain  2nd      full sender  [See $x macro]     host  [See hostnames]     of macros  2nd      meaningful, declared for rule sets      symbolic, for delivery agents      unqualified  2nd      user  [See user names] NDBM compile-time macro  ndbm database  NEED... compile-time macros  Nemeth, Evi  nested macro conditionals  NET... compile-time macros  netinfo database type  network interfaces, probing  network support  networks      forwarding messages over  NETX25 compile-time macro  newaliases command  2nd  3rd  NEWDB compile-time macro      defined automatically  newlines  [See whitespace] news, mailing list gateways to  nf files  nice, N= delivery agent and  NIS compile-time macro  nis database type  NISPLUS compile-time macro  nisplus database type  NNTPSERVER variable  no mailer in parsed address error message  no_default_msa feature  NO_GROUP_SET compile-time macro  nobody user  nocanonify feature  nodns feature  NOFTRUNCATE compile-time macro  non-local, aliases  NOTIFY command (SMTP)  NOTIFY extension, DSN  notsticky feature  NOTUNIX compile-time macro  nouucp feature  2nd  nrcpts= equate (syslog output)  nsd database database-map  nslookup program  ntries= equate (syslog output)  null addresses  null bytes, F=1 delivery agent flag and  null database type  nullclient feature  numbers  [See also identifier]     declared for rule sets      delivery failure count      inode and device  numeric-type arguments