I have a 3-rd party program, which connect to CAS server thru smtp for sending batch of e-mails. It began to work, but after 30-40 e-mails stop transfering, with "remote socket error" in CAS`s receive connector logs. I checked default frontend receive connector, and have changed "maxinboundconnectionspersource" from 20 (default) to unlimited and "maxinboundconnectionpercentagepersource" from 2 to 100% still without success. Before ms exchange 2013 has exchange 2010 with the same parameters on CAS/HUB default receive connector and all worked fine.
Please help to resolve this issue.