Best Practices for Migrating from Google Workspace / M365 to Stalwart

[gokul5557]

Hello Stalwart Team and Community,

We are building a hosted email service on top of the excellent Stalwart Mail Server and are planning the onboarding process for new clients.

A key part of this is migrating existing data from major providers like Google Workspace, Microsoft 365, and Zoho. I've researched standard practices but would appreciate the community's confirmation and insights specific to Stalwart.

Migration Tools: I understand Stalwart itself doesn't include a built-in migration GUI. Is the consensus that using a well-established tool like imapsync is the recommended and most effective method for importing mailboxes (including folders, messages, flags) via IMAP?

Authentication for Source Providers: Modern providers require OAuth 2.0 or app passwords for IMAP access.

Is it correct that Stalwart, as the destination server, doesn't need any special OAuth configuration for this? The OAuth flow is handled entirely between the migration tool (e.g., imapsync) and the source provider (Google/Microsoft).

Therefore, the best approach is to configure imapsync with OAuth 2.0 credentials (for a smoother process) or have the client's admin generate app passwords (as a fallback) for the source, while using standard Stalwart mailbox credentials for the destination.

Security & Automation: For those offering this as a service, what are the best practices for handling credentials/tokens securely during bulk migrations? Any tips on automating user creation via the Management API alongside the data migration process?

Our goal is to create a secure, client-friendly onboarding path where the organization's admin provides the necessary access (preferably via OAuth grant) without sharing user passwords.

Any guidance, experiences, or pointers would be immensely helpful.

Thank you for your time and for building a fantastic project.

[mdecimus]

Hi,

I can help you with your first question:

Migration Tools: I understand Stalwart itself doesn't include a built-in migration GUI. Is the consensus that using a well-established tool like imapsync is the recommended and most effective method for importing mailboxes (including folders, messages, flags) via IMAP?

Creating a migration tool from other mail servers is on the roadmap. In the meantime, what most people use to migrate is imapsync.