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src/mail/ngx_mail_proxy_module.c

diff --git a/src/mail/ngx_mail_proxy_module.c b/src/mail/ngx_mail_proxy_module.c
index 9f5a2f6..3cac329 100644
--- a/src/mail/ngx_mail_proxy_module.c
+++ b/src/mail/ngx_mail_proxy_module.c
@@ -171,6 +171,8 @@
         return;
     }
 
+    s->out.len = 0;
+
     switch (s->protocol) {
 
     case NGX_MAIL_POP3_PROTOCOL: