--- libESMTP-1.1.0.orig/meson.build	2021-06-04 18:18:50.000000000 +0200
+++ libESMTP-1.1.0/meson.build	2024-02-24 14:07:23.535476167 +0100
@@ -63,6 +63,7 @@ add_project_arguments(cc.get_supported_a
 ################################################################################
 dldep = cc.find_library('dl')
 ssldep = dependency('openssl', version : '>=1.1.0', required : get_option('tls'))
+ntlmdep = dependency('openssl', version : '>=1.1.0', required : get_option('ntlm'))
 threaddep = dependency('threads', required : get_option('pthreads'))
 
 #XXX add test for libbind9.so
@@ -71,6 +72,7 @@ lwresdep = cc.find_library('lwres', requ
 deps = [
   dldep,
   ssldep,
+  ntlmdep,
   threaddep,
   lwresdep,
 ]
@@ -220,8 +222,13 @@ include_dir = include_directories('.')
 subdir('login')
 subdir('plain')
 subdir('crammd5')
-if ssldep.found()
-  subdir('ntlm')
+
+if ntlmdep.found()
+  if cc.has_header('openssl/md4.h') and cc.has_function('MD4_Init', dependencies : ntlmdep)
+    subdir('ntlm')
+  else
+    error('MD4 is not supported in current openssl, unable to build NTLM plugin')
+  endif
 endif
 
 ################################################################################
@@ -247,4 +254,6 @@ summary({'current:revision:age': libesmt
 	 'STARTTLS': ssldep.found(),
 	 'CHUNKING': get_option('bdat'),
 	 'ETRN': get_option('etrn'),
-	 'XUSR': get_option('xusr')})
+	 'XUSR': get_option('xusr'),
+	 'NTLM': ntlmdep.found()})
+