--- php-7.3.24/acinclude.m4~	2020-11-09 14:38:20.000000000 +0200
+++ php-7.3.24/acinclude.m4	2020-11-09 14:39:53.522036584 +0200
@@ -1731,8 +1731,10 @@
 dnl Search for the sendmail binary.
 dnl
 AC_DEFUN([PHP_PROG_SENDMAIL], [
-  PHP_ALT_PATH=/usr/bin:/usr/sbin:/usr/etc:/etc:/usr/ucblib:/usr/lib
-  AC_PATH_PROG(PROG_SENDMAIL, sendmail, /usr/sbin/sendmail, $PATH:$PHP_ALT_PATH)
+  if test -z "$PROG_SENDMAIL"; then
+    PHP_ALT_PATH=/usr/bin:/usr/sbin:/usr/etc:/etc:/usr/ucblib:/usr/lib
+    AC_PATH_PROG(PROG_SENDMAIL, sendmail, /usr/sbin/sendmail, $PATH:$PHP_ALT_PATH)
+  fi
   PHP_SUBST(PROG_SENDMAIL)
 ])