Businesses that want to run an on-premise email solution alongside G Suite are looking to either:
1. Test G Suite while running their existing mail solution as an interim transitional step between a on-premises email solution and a full hosted email solution.
2. Use G Suite as a back-up to their on-premise solution, such as Exchange
Both scenarios are definitely possible with G Suite. G Suite generally provides the flexibility to do whatever you need to do with your email, it's just a question of how much configuration you have to do on your end for your specific business needs. Once everything is in place, and incoming/outgoing email is being captured in G Suite, you will be able to move over seamlessly to G Suite should the need arise. We think that as you come to be comfortable with the cost, reliability, and convenience of Google-hosted email, you and your users will be able to transition over to G Suite as a complete solution.
You can either a) route your domain's mail with an MX record change directly to G Suite, and have it delivered to G Suite mailboxes, and then passed onto your existing server,
or b) set up an intermediary mail gateway that can dual-deliver mail to both G Suite and your existing mail server. This should ensure that incoming mail is available in both systems.
For outbound mail, you will have to set up your existing mail system to send your domain's mail through G Suite.
We also have a directory sync tool via a Single-Sign-On (SSO) API so that your business' active directory integrates seamlessly alongside G Suite. G Suite Single Sign-on API lets you:
- Integrate your own authentication or LDAP system with G Suite and securely login your users to G Suite based on your own security standards
- Integrate with leading web single sign on systems, or facilitate authentication via Active Directory or other directory servers.
- Integrate G Suite with websites that have their own username and authentication mechanisms, eliminating the need for users to log in multiple times.
If you are interested in deploying G Suite, but require SSO or LDAP integration, we recommend one of two solutions:
1. You can use the SSO API to sync users' names and passwords when a user sets them on your system. While this will not keep your users' passwords exactly in sync, it does allow our system to have the same password as your sso. This also allows for increased access to our system beyond the web interface.
2. G Suite's SAML 2.0-based SSO integration allows you to hold all your users' accounts and passwords without the need for G Suite to hold any user passwords.