Some have said that Microsoft plans to move away from MAPI. I don’t believe Microsoft is moving away from MAPI any time soon. Currently, there are an estimated 500 million Microsoft Outlook users. Outlook uses MAPI to connect to Exchange. Even using Outlook remotely (RPC over HTTP), you are still using the MAPI protocol via plain RPC or RPC embedded within an HTTP data stream.
For this reason I recommend a email archive product that uses MAPI technology.
Other products use Transaction Log parsing. Although, this works, it is not using Microsoft’s best practices approach. Essentially developers are reverse engineering the Exchange undocumented Transaction Logs to extracting data for archival. Using this method can result in a major problems for this type of archive product if for some reason you need to restore Exchange data from a backup.
For this reason I recommend that you do not select an email archiving product that parses the Exchange Transaction Logs.
Many people are worried about email archiving adding extra overhead to your Exchange server. Both archiving methods, using MAPI or Parsing Transaction Logs , do add a certain additional load to a server. But we have not seen this cause problems. In most cases, most organizations have too much data in their Exchange server and using a good email archiving product eliminates this unnecessary data and actually makes the Exchange server perform better.
If you have questions or would like to look at email arching, please feel free to contact me.