In an attempt to better understand SMB's perspective on email archiving, GFI, an IT security and messaging software developer in the UK, conducted a survey which found mixed results:

51% of organisations who have not implemented email archiving, it appears that this is principally through lack of education. With budget restraints being the most popular reason for not purchasing (28%), a further combined 32% of those surveyed perceive it as unnecessary to their particular needs or feel too ill-informed to purchase.

Almost no respondents reported negative experiences (1%) so that isn't a barrier to adoption. With almost one-third of respondents not seeing any business need, there is a significant lack of understanding about the need for basic electronic record keeping.

Vella [GFI's Director of Product Management] concludes, "Email archiving is a function that should run through all company departments - obviously storage, backups, problematic and corrupt PST files, overloaded email servers and performance are the IT department's major concerns, while the legal team sees email as an essential factor in its discovery, disclosure and due diligence strategies. Indeed, most of our respondents who have implemented email archiving are doing so for compliance or for ensuring they have a full paper trail should there be any form of investigation.

The full survey report is available here.

SMBs in the US face similar considerations. For more on Federal Rules of Civil Procedures and how they apply to email, see this whitepaper from Inboxer.