Information about MAC client:1) Mac OS X Version 10.4.9 Intel Core 2 Duo Processor Mail Version 2.1.1 (752.3) 2) Mac OS X Version 10.4.9 PowerPC G5 Mail Version 2.1 (752/752.2)
ANSWERDisabling the SSL reuse option helps resolve the problem on Mac OS Mail client for SSL imaps connection.
no ssl settings reuse <VHOST>