I have used Symantec Enterprise Vault in the past, and it was fine... But with a tighter budget at my current place of employment, we have decided to utilize a tool we already have.. Adobe Professional
The PDF Maker will allow you to create a PDF from Multiple Emails or Entire Folders. It turnes them into a collection.
1) These PDF's are Searchable
2) They are accessible by anyone that access to the folder in which they were saved. We typically do this when we are closing out a Construction Job...