We're switching back to an MSP for a bit with Exchange 2013. Then we're looking at other solutions. So far this is looking like it's going to be something in ho

We're switching back to an MSP for a bit with Exchange 2013. Then we're looking at other solutions. So far this is looking like it's going to be something in house. "quite well" isn't an option for us. We need something reliable. We have had exactly that experience; things disappearing for hours at a time. There are absolutely no mail services with good web interface. This is the problem. We really want standard bits of glue that work across the board so we're looking at CalDAV, CardDAV and IMAP separately all using OpenLDAP SSO. Sharepoint is already canned; we ended up using Atlassian Confluence as we're already a JIRA user.