Make no mistake: moving from an on-premises Microsoft Exchange deployment to switch in the cloud is really a gargantuan undertaking. This year earlier, I explored the major issues you’ll have to consider and decisions you’ll have to make when moving to hosted Exchange.

But also for most folks, further guidance is essential. What are a number of the gotchas to consider? What are some guidelines to factor into your planning? Here, I’ll have a look at a number of important do’s and don’ts with regards to getting the organization into Exchange Online.

Note: This story targets migrating from Exchange Server on-premises for some version of Microsoft’s hosted Exchange service (under an Exchange Online , Office 365 , or Microsoft 365 subscription), or even to a hybrid configuration with the “365” apps in the cloud and Exchange remaining in a few fashion on-premises in production. It isn’t intended to connect with migrations to other providers’ services.

Don’t underestimate enough time it will take to go all your data over.

Depending on several factors, including just how many users you have, just how much data each mailbox has stored, bandwidth constraints, and much more, migrating email to the cloud may take from a couple of days to many weeks anywhere. One unexpected slowdown will come from Microsoft itself: a non-obvious protective feature of Exchange Online is that it throttles inbound sustained connections to be able to prevent a small amount of bad actors from overwhelming the machine.

Once you’re ready to go and in the cloud for production fully, you shall arrived at appreciate this defense, which works for the advantage of the overall subscription base. However when you are attempting to ingest data you will notice transfer rates sometimes slow to a crawl. There’s unfortunately little you can certainly do about this apart from simply endure. Make sure to include this in your planning, as moving hundreds or a large number of multi-gigabyte mailboxes into Exchange Online might take a lot longer than you may expect.

Do work with a delta-pass migration.

Decrease the right time pressure on yourself, if you can, with a delta-pass migration when compared to a strict cutover migration rather. With delta-pass migration, multiple migration attempts are created while mail has been delivered on-premises still. From Sunday the initial pass might move everything, May 1 backward, for instance, and another pass is manufactured later in the week to go the “delta” – or changes – from Sunday, Through Wednesday may 1, May 4, and another and another before mailboxes are current essentially.

This can be a useful technique, as each successive migration batch is smaller compared to the last. A weekend typically over, your last delta batch shall finish in a minute, and your moves are complete and you may throw your MX records to Exchange Online. Your users experience missing historical mailbox data never, because before mailboxes are identical, they utilize the mailbox that holds their data.

Don’t forget to configure edge devices and intrusion detection systems to identify Exchange Online as a reliable partner.

If you forget this all-important step, your migrations may be interrupted because your IDS thinks a denial-of-service attack is going on. Conveniently, Microsoft provides a regularly updated set of IP addresses utilized by all 365 services to utilize specifically when configuring your edge devices to trust traffic where necessary.

Do run any office network health insurance and connectivity tests in advance.

Microsoft is rolling out a comprehensive tool that may alert one to routing or latency issues between you and the Microsoft 365 data centers. A suite is run by the tool of tests of speed, routing, latency, jitter, and much more on your network link with identify and isolate common conditions that may lead to a degraded experience – especially with voice applications – for Microsoft 365 users.

Any performance issues the tool finds will likely have a negative effect on the speed of one’s migration attempts and passes. Solving or mitigating any presssing issues you discover will speed up the complete project.

In a hybrid environment, do utilize the EAC in trade Online to initiate mailbox moves.

If you select a hybrid model for the deployment, you then will by definition involve some mailboxes on-premises (at the very least for a while) plus some in the cloud. In this scenario, it could be tempting to trust your old go-to Exchange Management Console to accomplish all your mailbox move work, shifting mailboxes back and forth. Don’t give in compared to that temptation; it’s far better pull mailboxes into the cloud from the web-based EAC in the Microsoft 365 administration center, than using outdated on-premises tools rather.

Don’t just forget about Outlook client version updates.

Updating an working office suite across a big enterprise is not any easy task and requires a while, this means there’s a prevalence of older copies of Outlook among your users often. Once you control your Exchange deployment, that’s fine, as the timing is controlled by you of one’s moves.

But among the “side gotchas” that is included with utilizing the cloud is that another person reaches decide the baseline degree of software that will use its services. Microsoft is actually pushing everyone toward the subscription-based Office suite (Microsoft 365 or Office 365) and from the old per-user perpetual volume licenses with the entire year attached (Office 2013, 2016, or 2019, for instance).

In fact, of October 2020 as, the business declared that Outlook 2013 and older versions are no more supported allowing you to connect to Office 365 and Microsoft 365 services. Although it won’t block these older clients actively, they “may encounter performance or reliability issues as time passes.” No telling when Microsoft will pull the plug entirely there’s.

So don’t just forget about developing a intend to update your clients to Office 2016 or beyond, or proceed to a subscription license and deploy those apps of the quantity license editions instead.

Do intend to implement two-factor authentication.

One of the primary advantages to moving to switch Online and Microsoft 365 may be the ability to use all the new security features obtainable in the cloud, the main of which undoubtedly is the capability to start two-factor authentication . 2FA minimises your attack surface once you transform it on significantly, and since Microsoft did every one of the rewiring of the directory and Exchange security model on its servers to create it work, all you need to accomplish is flip the switch and show your users where you can plug in their cellular phone numbers.

Better yet, utilize the Microsoft Authenticator app to lessen the security and social engineering risks of using SMS texts. But allow perfect function as enemy of the nice don’t. Deploying Authenticator across thousands of phones could be difficult, especially with BYOD remote-work and setups environments where employees don’t get access to an in-person help desk. In contrast, establishing SMS requires nothing from the ultimate end user and may be done entirely because of it. So if the decision is between two-factor authentication with SMS no two-factor authentication, you should start 2FA and use SMS then.

In a hybrid environment, remove your last Exchange Server don’t.

One cardinal rule of operating a hybrid Exchange environment is that you need to keep a minumum of one Exchange Server running on premises to be able to manage users. There is a real way to continue steadily to utilize the Active Directory attribute editing functionality to control recipients, but it’s not necessarily supported – and when it breaks, you’ll need to file a ticket with Microsoft, wait three days, and perhaps, just maybe, come back it’ll.

It is easier to utilize the Exchange admin console of one’s on-premises server to control recipients in a hybrid environment, and you also can’t do that if you don’t leave an Exchange Server running in your on-premises deployment. Microsoft has repeatedly said it’s focusing on a solution to the issue of needing to have a preexisting licensed server on-prem with hybrid deployments, but even with several years there has been little progress toward solving that problem.

The final word

A transition time is challenging always, and that is certainly true when migrating your company to Exchange Online. By factoring in the warnings and advice above, you’ll make that path smoother and reach quickly the final line more.