diff --git a/configure.in b/configure.in
index f455391be2b..33a58b43a98 100644
--- a/configure.in
+++ b/configure.in
@@ -1462,6 +1462,12 @@ AC_FUNC_ALLOCA
 # On HPUX 9.01, -lm does not contain logb, so check for sqrt.
 AC_CHECK_LIB(m, sqrt)
 
+# Check for mail-locking functions in a "mail" library
+AC_CHECK_LIB(mail, maillock,
+	     AC_DEFINE(HAVE_LIBMAIL)
+	     AC_CHECK_FUNCS(touchlock)
+	     AC_CHECK_HEADERS(maillock.h))
+
 AC_CHECK_FUNCS(gettimeofday gethostname getdomainname dup2 \
 rename closedir mkdir rmdir sysinfo \
 random lrand48 bcopy bcmp logb frexp fmod ftime res_init setsid \