We’re in the process of planning an Intermedia to Office 365 migration for a client and are looking for insights or recommendations from those who have gone through it. The current setup includes hosted Exchange email through Intermedia, and the goal is to migrate all mailboxes, calendars, and contacts into Microsoft 365 (Office 365) with minimal disruption.

While the Microsoft 365 Admin Center provides built-in tools, we’re considering using a migration partner like Apps4Rent, who offers managed migration services with end-to-end support. Their team claims to handle everything from mailbox transfers to DNS configuration, and even post-migration user support.

Has anyone here used third-party tools or providers for similar migrations? Specifically interested in how to handle large mailboxes, shared mailboxes, and domain verification without causing downtime. Any pitfalls to watch out for or tips to streamline the process?

Also, if there are any GleamTech tools or file-related components that could assist in managing data during the transition, I’d love to hear about them.

Thanks in advance for your advice or experiences—it’s much appreciated!