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Email migration to Office 365: Part 2 – The most common Office 365 migration mistakes

Dec 16, 2016 by Emma Robinson

Want to understand the scope and aims of your email migration project? Take at the first blog in this series here
Having decided that Office 365 email migration is the right decision for your organisation, what are the technical pitfalls that you should avoid? The most catastrophic scenarios are those where the migration has only been planned around live mail, breaking all the dependencies with other elements of the email ecosystem. The missing bits have to be hurriedly retrofitted into the project, causing massive project delays, increased risk of downtime, and huge additional costs.
Live email
Theoretically it’s easy to migrate live email as Microsoft provides basic tools that allow you to transfer data into Office 365/Exchange Online environment, although large cutover migrations are especially difficult.
The trouble is that you need to consider more than your live mail. In many organisations, email is often the default ‘database of record’. It’s the only application that every single employee actively uses in order to do his or her job. Not only does it provide an audit trail of correspondence, but it’s also used by many people as a quick way of accessing other documents, rather than filing attachments away.
You need to find a way of integrating your live mailbox migration with other elements of the email ecosystem from the outset if you are to avoid difficulties further down the line.
Over time, archiving of older emails in purpose-built electronic systems like Veritas Enterprise Vault often becomes essential to retain performance of the main system. It’s easy to break the interactive shortcuts (or ‘stubs’) that users rely on if just the live mail system is moved.
Many organisations are now migrating archives wholesale into Office 365 – which creates the risk of incredible throughput bottlenecks and business interruption – while others have to remap their live mail and archive systems completely if a hybrid Office 365 with on-premises archive is the target solution. Both scenarios can be achieved painlessly if the right approach is taken from the outset.
Offline ‘PST’ files
The ubiquity of Microsoft Outlook and Exchange over the past 20 years created another problem. Emails are also stored in files with.pst extensions on local users’ machines. That means there can be many thousands of unsecured and untracked ‘PST’ files containing sensitive data scattered around the organisation.
If PST eradication is not included in your Office 365 migration plan then the organisation may find itself unable to fulfil legal obligations on retrievability, because PSTs cannot be backed up centrally. You’ll also be at heightened security risk. In the high-profile 2014 Sony Pictures hack, at least 179 ‘PST’ files – including those of an executive at Sony Pictures Canada and one of its IT audit supervisors, along with many archive and backup PST files – were stolen. At least 170,000 individual emails were subsequently published by Wikileaks, and Sony reputedly had to set aside $15m to deal with the incident’s fallout.
Public folders
Exchange public folders have been commonly used to share and collaborate for over 20 years. They typically build up plenty of redundant data spanning extremely large hierarchies and volumes, and can be very difficult to manage. Public folders don’t provide versioning or other document management features, such as controlled check-in and check-out functionality, and automatic notifications of content changes. Migration is complicated by the need to arrange data logically for eDiscovery and compliance.
By the time Exchange Server 2010 was released, public folders had already become an optional feature, and in 2014 Microsoft decided the time was right to turn off its own last on-premises public folders.
Tony Redmond, Microsoft MVP and all-round Exchange Guru suggests one target for public folders is Office 365 groups. According to Tony, a group is:
“…a combination of a distribution group and a site mailbox (or even a traditional shared mailbox) because when we look under the hood, we find elements of Exchange and SharePoint mixed together to deliver the collaborative potential that Microsoft envisages for Office 365 Groups. Recent comments by Microsoft indicate that groups are preferred to site mailboxes if you need a collaboration platform for a new project.”
Later in this series we’ll be examining some of the technical considerations around migrating large amounts of data into Office 365, how you should research and choose appropriate tools to manage the migration, and we’ll also be providing a checklist to help you ensure you are ready to migrate.
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