I like that it is easy to set up, works great with Gmail accounts (and other providers), has an excellent interface for searching archived mail messages & attachments within my organization's account(s). It does not work well when you have multiple domains or services under one organizational umbrella - all sent emails are stored in just 1 mailbox regardless of where they originated from / were processed at by your business' various applications/services etc.. The only way around this would be if each service had its own separate "Mail Vault" subscription which could then aggregate them together but thats another story! Our employees use their personal gmail addresses as part of our corporate domain so we need something simple yet secure enough to hold everything related back through time without having issues storing large volumes data over long periods such as years beyond 5 yrs old!