diff --git a/git-send-email.perl b/git-send-email.perl
index f5ba4e7699..c4f1dfbd7a 100755
--- a/git-send-email.perl
+++ b/git-send-email.perl
@@ -897,7 +897,7 @@ X-Mailer: git-send-email $gitversion
 
 	if ($dry_run) {
 		# We don't want to send the email.
-	} elsif ($smtp_server =~ m#^/#) {
+	} elsif ($smtp_server =~ m#^/# || $smtp_server =~ m#[a-zA-Z]\:#) {
 		my $pid = open my $sm, '|-';
 		defined $pid or die $!;
 		if (!$pid) {