I am getting these messages in my MSBLOGS for my IMAP 4 connection between Nupoint 18.00.49.01 and Exchange 2013 CU11. Exchange does have a load balancer. Some connections are good for several connections then I get one that says "read failed Socket Disconnected"
24/May/16 13:57:50.178 imapTraffic DEBUG [21171:f18f6b70]../Imap4Adapter/imap4Client.cpp#0891: [f18f6b70] Snd: MSB1 LOGIN "afbank/nupoint/dbarr" "****"
24/May/16 13:57:50.279 imapTraffic DEBUG [21171:ef0f2b70]../Imap4Adapter/imap4Client.cpp#3377: [ef0f2b70] Rcv: MSB1 OK LOGIN completed.
24/May/16 13:57:50.279 imapTraffic DEBUG [21171:ef0f2b70]../Imap4Adapter/imap4Client.cpp#1044: [ef0f2b70] Snd: 2 SELECT INBOX
24/May/16 13:57:50.282 imapTraffic DEBUG [21171:f18f6b70]../Imap4Adapter/imap4Client.cpp#3377: [f18f6b70] Rcv: MSB1 OK LOGIN completed.
24/May/16 13:57:50.282 imapTraffic DEBUG [21171:f18f6b70]../Imap4Adapter/imap4Client.cpp#1044: [f18f6b70] Snd: 2 SELECT INBOX
24/May/16 13:57:50.354 imapAdapter DEBUG [21171:ea562b70]../Imap4Adapter/imap4SSLTransport.cpp#0596: [e80c4058] IMAP4 Read failed -> Socket Disconnected
24/May/16 13:57:50.355 imapAdapter DEBUG [21171:ea562b70]../Imap4Adapter/imap4Client.cpp#7546: [ea562b70]:[e80c4058] IMAP4 ReadIdleData failed to receive socket data
