Initially, email systems merely stored curent email. Email, once read, was normally deleted.
By about 2000, message stores started to be used to keep old emails. They thus grew substantially in size. The ability to offload emails to a secondary repository, or archive, evolved as a result.
Initially, the main motivation for email archiving was mainly to keep Microsoft Exchange mailboxes small: ie, “storage management”. For performance reasons, mailboxes usually had to be kept to 30MB to 100MB (!). An archiving product could remove mail from a user’s message store, while still making the email available in the archive.
By about 2005, the main reasons for archiving had become:
- Regulatory compliance. Formal corporate records were increasingly in email format, and laws and regulations require that such information be preserved for specified periods
- E-Discovery. Legal processes required the ability to quickly retrieve email relevant to a case
- Storage management. To be able to offload rarely-accessed information from a user’s primary message store.
Archiving has also been gradually spreading to other human communications technologies, such as instant messaging and Sharepoint teamspaces. Email archiving remains the most important type of archiving, however.
As of 2012, archiving remains a time-consuming and expensive business for the IT community.