diff --git a/lib/pop3.c b/lib/pop3.c
index 0581c58b019d85a3bad66c00be7fe6dbb284e19d..dc5a1c2fa2165cd319a56de62921108a811aaa40 100644
--- a/lib/pop3.c
+++ b/lib/pop3.c
@@ -481,11 +481,14 @@ static CURLcode pop3_list(struct connectdata *conn)
   CURLcode result = CURLE_OK;
   struct pop3_conn *pop3c = &conn->proto.pop3c;
 
-  result = Curl_pp_sendf(&conn->proto.pop3c.pp, "LIST %s", pop3c->mailbox);
+  if(pop3c->mailbox[0] != '\0')
+    result = Curl_pp_sendf(&conn->proto.pop3c.pp, "LIST %s", pop3c->mailbox);
+  else
+    result = Curl_pp_sendf(&conn->proto.pop3c.pp, "LIST");
   if(result)
     return result;
 
-  if(strlen(pop3c->mailbox))
+  if(pop3c->mailbox[0] != '\0')
     state(conn, POP3_LIST_SINGLE);
   else
     state(conn, POP3_LIST);
diff --git a/tests/data/test810 b/tests/data/test810
index d4f75972a7bca45d5f3d734bbd18833af7a25330..1c31042b69ff47c60243deca18d41e89ee7b118f 100644
--- a/tests/data/test810
+++ b/tests/data/test810
@@ -38,7 +38,7 @@ pop3://%HOSTIP:%POP3PORT/ -u user:secret
 <protocol>
 USER user
 PASS secret
-LIST 
+LIST
 QUIT
 </protocol>
 </verify>
diff --git a/tests/data/test811 b/tests/data/test811
index 850e5e27d306feb132d2b502d25c2497f830cd9d..ca107abccc8b984887ba33198f13d071bac98fda 100644
--- a/tests/data/test811
+++ b/tests/data/test811
@@ -36,7 +36,7 @@ pop3://%HOSTIP:%POP3PORT/ -u user:secret
 <protocol>
 USER user
 PASS secret
-LIST 
+LIST
 QUIT
 </protocol>
 </verify>