fix typo
diff --git a/src/mail/ngx_mail.h b/src/mail/ngx_mail.h
index 1a401bc..a6b78a5 100644
--- a/src/mail/ngx_mail.h
+++ b/src/mail/ngx_mail.h
@@ -102,7 +102,7 @@
     ngx_pop3_auth_login_password,
     ngx_pop3_auth_plain,
     ngx_pop3_auth_cram_md5
-} ngx_po3_state_e;
+} ngx_pop3_state_e;
 
 
 typedef enum {