1. Importing a lot of large mailboxes will take time. Start the process a few weeks in advance and import the data out of hours to ensure your existing mail server keeps running until the migration is complete.
  2. Exchange Server users can keep their Outlook users happy when migrating from an Exchange Server. When going through the verification process and setting a new Outlook Profiles up, make sure it looks at the “autodiscover” record before looking at Office 365. With good preparation and good decisions about when to start the process, it will be business as usual for your Outlook users.
  3. When you go to add your domain name to your new Office 365 account it will ask you to prove you own your domain, so you need to ensure you are able to verify it. You can do this by going to whois.com, enter the domain to find the Name Servers e.g. ns.123-reg.co.uk. You can then logon to the Name Servers control panel, and add the TXT or MX record you can use to verify the domain.
  4. Decide from your email addresses, what are actual mailboxes. Many of them might just be aliases (addresses that forward to the same mailbox), distribution lists or shared mailboxes. When you migrate to Office 365 its best to start with an accurate list so that you only pay for the ones that you need.
  5. When migrating your emails from your old system to Office 365, there are different options for importing old emails. Consider numbers of mailboxes, amount of mail in each, and whether you want to import just emails or contacts, calendars and tasks as well!
  6. Consider Data Protection and G.D.P.R. obligations. Office 365 has a useful archiving function (also called Messaging Records Management or MRM policy) that when enabled, the default policy automatically does the following:
    • Moves items two years or older to the users archive mailbox.
    • Moves items 14 days or older from the Recoverable Items folder in the user's primary mailbox to the Recoverable Items folder in their archive mailbox.
    Whist this is very useful for a lot of clients, if you have emails with “personal data” you may want to consider creating an archiving policy appropriate for the nature of your work.
    Office 365 email hosting features
  7. When you’ve decided what your archive policy is going to be you will need to configure and enable it when you set mailboxes up. Making use of the mailbox archive will effectively double your storage space for free; and it even automatically recreates the same folder structure for the archive so it’s easy to find your archived emails! For example, you could set rules that:
    • Move email to archive after 3 years
    • Remove items from archive after 7 years
    • Delete anything in junk after 6 months
    • Permanently delete your deleted items after 3 months
  8. Ask your users to prepare a strong password and use the standard two factor authentication to keep your accounts secure.
  9. Don’t give user accounts global admin access. Create separate accounts with administrative privileges to keep your other accounts secure if one account is compromised.
  10. Finally, we suggest that you let us do it for you, whilst you get on with running your business!

With good preparation, you should be able to migrate all your mailboxes with absolutely no downtime for your staff and no loss of emails!


Get in touch today to discuss your Office 365 email migration. We can help every step of the way.

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