Hello, some emails stay in mail queue. I found this message in maillog: System_resources_temporarily_unavailable._(#4.3.0) I done some research an found some answers in this thread: http://forum.parallels.com/pda/index.php/t-110308.html But this thread speak about plesk 10.2. I have version 10.4.4 MU #4. It seems that problem persist. Is enabling of IPV6 right solution? Please, can somebody help me with this? My system: Linux 2.6.9-023stab052.4-smp Plesk 10.4.4 MU #4 Thank you for help.