Hello! We are using several OTRS installs (on one server) with a dedicated database server. Mails are fetched with the PostMasterMailbox.pl. Since we had a server problem and had to reset/reboot it, 2 of 8 OTRS stopped getting new mails. In the System Log, we have this entry: Can't create PID PostMasterMailbox, because it's already running (support-new.panfu.nl/4123)! In fact, there are some PostMasterMailbox.pl processes running. Killing these processes and deleting the entry in the process_id table in the database does not fix this issue. Executing ./PostMasterMailbox.pl -f 1 -d 3 manually gives this output: Notice: PostMasterMailbox.pl is already running but is starting again! Net::POP3>>> Net::POP3(2.28) Net::POP3>>> Net::Cmd(2.26) Net::POP3>>> Exporter(5.58) Net::POP3>>> IO::Socket::INET(1.29) Net::POP3>>> IO::Socket(1.29) Net::POP3>>> IO::Handle(1.25) Net::POP3=GLOB(0x20a24b50)<<< +OK POP3 Ready mailserver.example.com 0001ee64 Net::POP3=GLOB(0x20a24b50)>>> USER otrs_xx@example.com Net::POP3=GLOB(0x20a24b50)<<< +OK USER otrs_xx@example.com set, mate Net::POP3=GLOB(0x20a24b50)>>> PASS .... Net::POP3=GLOB(0x20a24b50)<<< +OK You are so in Net::POP3=GLOB(0x20a24b50)>>> STAT Net::POP3=GLOB(0x20a24b50)<<< +OK 5800 30295323 Net::POP3=GLOB(0x20a24b50)>>> LIST Net::POP3=GLOB(0x20a24b50)<<< +OK POP3 clients that break here, they violate STD53. POP3: Message 1/5800 (otrs_xx@example.com/mailserver.example.com) Net::POP3=GLOB(0x20a24b50)>>> LIST 1 Net::POP3=GLOB(0x20a24b50)<<< +OK 1 1859 Net::POP3=GLOB(0x20a24b50)>>> RETR 1 Net::POP3=GLOB(0x20a24b50)<<< +OK 1859 octets follow. And now, the process is hanging endless. In one OTRS System Log is a message saying that a filter is applied to this message but it does not appear in any queue. In the other OTRS, no filter is applied to the message and it it does not appear in any queue either. We could exclude the possibility that this issue is caused by a specific mail. It happens always and with every mail. Has anyone an idea what could cause such an issue? Regards, SW.