diff --git a/usr.bin/mail/extern.h b/usr.bin/mail/extern.h
--- a/usr.bin/mail/extern.h
+++ b/usr.bin/mail/extern.h
@@ -131,7 +131,6 @@
 uid_t	 getuserid(char *);
 int	 grabh(struct header *, int);
 int	 group(void *);
-void	 hangup(int);
 int	 hash(const char *);
 void	 hdrstop(int);
 int	 headers(void *);
diff --git a/usr.bin/mail/lex.c b/usr.bin/mail/lex.c
--- a/usr.bin/mail/lex.c
+++ b/usr.bin/mail/lex.c
@@ -199,8 +199,6 @@
 	if (!sourcing) {
 		if (signal(SIGINT, SIG_IGN) != SIG_IGN)
 			(void)signal(SIGINT, intr);
-		if (signal(SIGHUP, SIG_IGN) != SIG_IGN)
-			(void)signal(SIGHUP, hangup);
 		(void)signal(SIGTSTP, stop);
 		(void)signal(SIGTTOU, stop);
 		(void)signal(SIGTTIN, stop);
@@ -567,17 +565,6 @@
 	}
 }
 
-/*
- * Branch here on hangup signal and simulate "exit".
- */
-void
-hangup(int s __unused)
-{
-
-	/* nothing to do? */
-	exit(1);
-}
-
 /*
  * Announce the presence of the current Mail version,
  * give the message count, and print a header listing.