diff -urN ../exim-4.87.orig/src/deliver.c ./src/deliver.c
--- ../exim-4.87.orig/src/deliver.c	2016-04-02 21:24:15.000000000 +0200
+++ ./src/deliver.c	2016-08-03 00:07:08.763548000 +0200
@@ -8065,7 +8065,7 @@
 
 #ifdef SUPPORT_TLS
 if (!regex_STARTTLS) regex_STARTTLS =
-  regex_must_compile(US"\\n250[\\s\\-]STARTTLS(\\s|\\n|$)", FALSE, TRUE);
+  regex_must_compile(US"(^|\\n)250[\\s\\-]STARTTLS(\\s|\\n|$)", FALSE, TRUE);
 #endif
 
 #ifndef DISABLE_PRDR
diff -urN ../exim-4.87.orig/src/verify.c ./src/verify.c
--- ../exim-4.87.orig/src/verify.c	2016-04-02 21:24:15.000000000 +0200
+++ ./src/verify.c	2016-08-03 00:07:14.435680000 +0200
@@ -741,7 +741,7 @@
       if (esmtp && !suppress_tls &&  tls_out.active < 0)
 	{
 	if (regex_STARTTLS == NULL) regex_STARTTLS =
-	  regex_must_compile(US"\\n250[\\s\\-]STARTTLS(\\s|\\n|$)", FALSE, TRUE);
+	  regex_must_compile(US"(^|\\n)250[\\s\\-]STARTTLS(\\s|\\n|$)", FALSE, TRUE);
 
 	tls_offered = pcre_exec(regex_STARTTLS, NULL, CS responsebuffer,
 		      Ustrlen(responsebuffer), 0, PCRE_EOPT, NULL, 0) >= 0;