diff --git a/cf-execd/cf-execd-runner.c b/cf-execd/cf-execd-runner.c
index 574bcf7534c..04edb8f3ccf 100644
--- a/cf-execd/cf-execd-runner.c
+++ b/cf-execd/cf-execd-runner.c
@@ -797,7 +797,11 @@ static void MailResult(const ExecConfig *config, const char *file)
         {
             continue;
         }
-        if (send(sd, line, n_read, 0) == -1 ||
+        /* Dot-stuff lines starting with '.' (RFC 5321, section 4.5.2), or a
+         * lone "." in the output would end the DATA section early and the
+         * remaining lines would be read by the server as SMTP commands. */
+        if ((line[0] == '.' && send(sd, ".", 1, 0) == -1) ||
+            send(sd, line, n_read, 0) == -1 ||
             send(sd, "\r\n", 2, 0) == -1)
         {
             Log(LOG_LEVEL_ERR, "Error while sending mail to mailserver "
diff --git a/tests/acceptance/25_cf-execd/mail_dot_line.cf b/tests/acceptance/25_cf-execd/mail_dot_line.cf
new file mode 100644
index 00000000000..7d43a5c9c30
--- /dev/null
+++ b/tests/acceptance/25_cf-execd/mail_dot_line.cf
@@ -0,0 +1,44 @@
+# Tests that a line consisting of a single "." in the agent output is
+# dot-stuffed by cf-execd, so it does not end the SMTP DATA section early.
+body common control
+{
+  inputs => { "../default.sub.cf", "mailfilter_common.cf.sub" };
+  bundlesequence => { default($(this.promise_filename)) };
+}
+
+bundle agent init
+{
+  vars:
+    "reports" slist => { "CorrectString1$(const.n).$(const.n)CorrectString2" };
+    "includes" slist => {};
+    "excludes" slist => {};
+
+  methods:
+    "any"
+      usebundle => prepare_mailfilter_test(
+        @(reports), @(includes), @(excludes)
+      );
+}
+
+bundle agent test
+{
+  meta:
+    "test_soft_fail"
+      string => "windows",
+      meta => { "ENT-10215" };
+}
+
+bundle agent check
+{
+  vars:
+    "wanted" slist => { 'CorrectString1\r
+\.\.\r
+CorrectString2' };
+    "empty_list" slist => {};
+
+  methods:
+    "any"
+      usebundle => check_cf_execd_mail(
+        @(wanted), @(empty_list), $(this.promise_filename)
+      );
+}