[Minor] Fix grammar rule

diff --git a/src/ragel/smtp_base.rl b/src/ragel/smtp_base.rl
index 9ff2314508a3af68ac33bc0d189fef1d0876ff9f..eefc430d5b67879c835dee2457cac22117c88f94 100644 (file)
--- a/src/ragel/smtp_base.rl
+++ b/src/ragel/smtp_base.rl
@@ -26,7 +26,7 @@
 
   dcontent       = 33..90 | 94..126 | UTF8_non_ascii;
   Let_dig        = alpha | digit | UTF8_non_ascii;
-  Ldh_str        = ( alpha | digit | "_" | "-" )* Let_dig;
+  Ldh_str        = ( Let_dig | "_" | "-" )* Let_dig;
 
   quoted_pairSMTP  = "\\" 32..126;
   qtextSMTP      = 32..33 | 35..91 | 93..126 | UTF8_non_ascii;