Allow to set the hostname sent to the SMTP server with the HELO command for mail notification (#165)

internal/config/config_test.go

@@ -75,6 +75,7 @@ func TestLoadFile(t *testing.T) {
 						Port:               25,
 						SSL:                utl.NewFalse(),
 						InsecureSkipVerify: utl.NewFalse(),
+						LocalName:          "localhost",
 						From:               "diun@example.com",
 						To:                 "webmaster@example.com",
 					},
@@ -371,6 +372,7 @@ func TestLoadMixed(t *testing.T) {
 						Port:               25,
 						SSL:                utl.NewFalse(),
 						InsecureSkipVerify: utl.NewTrue(),
+						LocalName:          "localhost",
 						From:               "diun@foo.com",
 						To:                 "webmaster@foo.com",
 					},