For creating the safe gmail backup,  I used Gmail Backup Tool by MailsDaddy to save all my personal emails before deleting an old Gmail account. It worked perfectly—simple interface, fast backup, and it even kept the attachments and read/unread status. I chose the PST format, but it offers others too. Great tool, really reliable.

If you want to migrate cross-tenant without relying on any third party, there’s an alternative solution: a manual option that allows you to complete the migration without any disruption. Manual Office 365 Tenant-to-Tenant Migration demands careful planning for a seamless transition. The process includes migrating crucial data like emails, calendars, contacts and OneDrive files data using Microsoft tools such as PowerShell. Key steps involve configuring the source and target tenants, setting up permissions, updating DNS records, and validating data after migration. Pre-migration testing and clear communication with users are essential to minimize downtime and ensure a smooth experience. For step-by-step instructions, visit office365solutions website