Methods to Route Email in G Suite for Your Organization
This Article explores the various ways to configure mail routing for your organization. Routing is used to configure inbound, outbound, and internal delivery options, such as dual delivery and split delivery.
Route incoming email
As a G Suite administrator, you want to control how email for your organization is routed and stored. You can customize routing and delivery to suit your organizational requirements.
You can Route your incoming emails using different delivery methods described here.
You may use this method if your organization is exclusively using Gmail. It is the default configuration for incoming emails addressed to G Suite users and delivers emails directly to the respective recipients’ Gmail inboxes. In case an email is addressed to a user who isn't a G Suite user in your organization, the mail server discards the message, unless you have configured a catch-all address to receive misaddressed messages.
Route messages using split delivery
In case of split delivery, an incoming message is delivered to either a Gmail inbox or a legacy server inbox, depending on the recipient.
This method works well if some of your users use Gmail, and others use a different mailing solution. Also, Split delivery works well if you are migrating to Gmail from a legacy mail server and you plan to execute a test with a subset of users. You can set up a catch-all routing rule for unregistered users in order to receive messages.
Set up mail dual delivery
As an administrator, if you need to deliver email messages to 2 or more inboxes, you should set up dual delivery. Users will be receiving messages in a Gmail inbox and a non-Gmail inbox or an external server.
How dual delivery works
In dual delivery, incoming mail is delivered to a primary mail server first. The primary server delivers each message to the inboxes associated with it, then forwards all messages to a secondary mail server. The secondary server delivers the messages to the secondary server inboxes.
The primary server is the mail server identified in the MX records for your domain.
Legacy server as primary server
Use Gmail as the primary server for dual delivery. If in case you use your legacy server as primary, don't update your MX records to Google.
Set up a catch-all address
A catch-all address is created to ensure that messages that are accidentally addressed to an incorrect email address for a domain can still be received.
Route messages to additional recipients
You can configure a routing rule to forward messages to additional recipients. You can make different settings for each user.
Set up non-Gmail mailbox delivery
It can be used to filter for spam and reroute all non-spam messages to your external mail server.
Users can log in to a Message Center and access their clean mail with their on-premise mailbox and have no access to a Gmail mailbox.
All of these settings can be tailored for different people and teams using organizational units.
As an administrator, you can set up a domain-wide routing policy for incoming mails. You can also define delivery routes based on a mail’s content or attachments.
If a mail is routed from a Gmail or G Suite server to an external recipient server and the connection cannot be established due to a time-out, refusal, or 400-series error, the mail will be placed in a queue and retried. Normally a retry attempt is repeatedly made every few minutes.
If you update your settings with a new host while a mail is still being retried, the mail will still be routed to the original server and not to the updated one.
Messages are kept in queue and retried for up to 7 days before they are returned to the sender. If there is a permanent failure such as 500-series error, the mail is instantly rejected.