Looking over the mirror log on the slave here is what I get - looks like it's a one way street and looks like the firewall may be blocking something. Port 110 is open. Are there any other ports that mirroring uses?
18 03:41:01.00:-1225409648: mirror: open (<Master IP
address>) waiting for 20 seconds for retry
18 03:41:01.00:-1225409648: mirror: Unable to open Open (<Master
IP address>) failed Operation now in progress 33 sec
18 03:41:21.00:-1225409648: mirror: open (<Master IP
address>)
18 03:41:55.00:-1225409648: mirror: open failed2 (Open (<Master
IP address>) failed Operation now in progress 34 sec)
18 03:41:55.00:-1225409648: mirror: open failed and took 34
seconds, check firewall etc
18 03:41:55.00:-1225409648: mirror: Unable to open Open (<Master
IP address>) failed Operation now in progress 34 sec
18 03:42:15.00:-1225409648: mirror: open (<Master IP
address>) waiting for 40 seconds for retry
18 03:42:15.00:-1225409648: mirror: Unable to open Open (<Master
IP address>) failed Operation now in progress 34 sec
18 03:42:35.00:-1225409648: mirror: open (<Master IP
address>) waiting for 20 seconds for retry
18 03:42:35.00:-1225409648: mirror: Unable to open Open (<Master
IP address>) failed Operation now in progress 34 sec
18 03:42:55.00:-1225409648: mirror: open (<Master IP
address>)
18 03:43:28.00:-1225409648: mirror: open failed2 (Open (<Master
IP address>) failed Operation now in progress 33 sec)
18 03:43:28.00:-1225409648: mirror: open failed and took 33
seconds, check firewall etc
18 03:43:28.00:-1225409648: mirror: Unable to open Open (<Master
IP address>) failed Operation now in progress 33 sec
18 03:43:48.00:-1225409648: mirror: open (<Master IP address>)
waiting for 40 seconds for retry
18 03:43:48.00:-1225409648: mirror: Unable to open Open (<Master
IP address>) failed Operation now in progress 33 sec
18 03:44:08.00:-1225409648: mirror: open (<Master IP
address>) waiting for 20 seconds for retry
18 03:44:08.00:-1225409648: mirror: Unable to open Open (<Master
IP address>) failed Operation now in progress 33 sec
18 03:44:28.00:-1225409648: mirror: open (<Master IP
address>)
18 03:45:01.00:-1225409648: mirror: open failed2 (Open (<Master
IP address>) failed Operation now in progress 33 sec)
18 03:45:01.00:-1225409648: mirror: open failed and took 33
seconds, check firewall etc
18 03:45:01.00:-1225409648: mirror: Unable to open Open (<Master
IP address>) failed Operation now in progress 33 sec
18 03:45:21.00:-1225409648: mirror: open (<Master IP
address>) waiting for 40 seconds for retry
18 03:45:21.00:-1225409648: mirror: Unable to open Open (<Master
IP address>) failed Operation now in progress 33 sec
18 03:45:41.00:-1225409648: mirror: open (<Master IP
address>) waiting for 20 seconds for retry
18 03:45:41.00:-1225409648: mirror: Unable to open Open (<Master
IP address>) failed Operation now in progress 33 sec
18 03:46:01.00:-1225409648: mirror: open (<Master IP
address>)