Fix hostname lookup for rdns rbl

diff --git a/src/plugins/lua/rbl.lua b/src/plugins/lua/rbl.lua
index c180898d4389235c766771fd113a6b38cf8f908b..0dcc48e7b5d2d429f3011270e913fbceb914da23 100644 (file)
--- a/src/plugins/lua/rbl.lua
+++ b/src/plugins/lua/rbl.lua
@@ -78,7 +78,7 @@ local function rbl_cb (task)
        end
 
        local sender_dns = task:get_hostname()
-       if sender_dns ~= nil then
+       if sender_dns ~= nil and sender_dns ~= 'unknown' then
                for k,rbl in pairs(rbls) do
                        if rbl['rdns'] then
                                task:get_resolver():resolve_a(task:get_session(), task:get_mempool(), sender_dns .. '.' .. rbl['rbl'], rbl_dns_cb, k)