Forward a Google Group (support@) to a Slack channel

Steps

1. 1

   Allow external members (Admin console)

   In the Google Admin console, go to Apps > Google Workspace > Groups for Business > Sharing settings, check "Group owners can allow external members" and "Group owners can allow incoming email from outside the organization", then Save.

2. 2

   Open the group to customers

   Go to Directory > Groups, open the support@ group, click Access Settings and Edit. Make sure Who can post includes External, turn on "Allow external members in the group", and Save. Since Google's 2026 change, only groups with external members allowed can have an outside address as a member.

3. 3

   Add the RelayMail address as a member

   In Google Groups (groups.google.com), open the group, click Members, then Add members. Leave "Directly add members" on, enter the forwarding address from your RelayMail setup page (inbox-...@relay.relaymail.app), and click Add members.

4. 4

   Check posting and moderation

   In the group's Group settings, confirm Who can post is Anyone on the web. Under Posting policies, make sure Message moderation is not holding outside senders, and check Spam message handling.

5. 5

   Send a test email

   Email support@ from an outside account. When it arrives, RelayMail confirms forwarding by itself and the email appears in the channel as a thread; reply there and the sender gets your reply by email.

Confirming the forward

Nothing to click. An address added directly (not invited) becomes a member right away; Google only sends it a notice. Don't use Invite: an invitation has to be accepted before the address joins. As an alternative to a member, an admin can add a Gmail routing rule for the group account with "Add more recipients" set to your RelayMail address (rule changes can take up to 24 hours). Replies you write in the Slack thread go out from noreply@relay.relaymail.app with Reply-To set to your support address, so the customer's answer comes back through the same forward into the same thread. To send replies as support@ itself, verify your domain in RelayMail (see the custom domain guide); that adds sending records for RelayMail and does not change where your inbound mail goes.

What to watch for

• Both organization-level external options are off by default. If customers' emails bounce or never arrive, the usual fix is Who can post set to Anyone on the web plus incoming email from outside the organization.
• A permission set to "Entire organization" leaves out outside senders, so Who can post must include External or customers' emails are rejected or held.
• When the sender's domain has a strict DMARC policy (p=reject or p=quarantine), Google delivers the message as "Sender via Group" with the group's address as the sender. RelayMail replies to the message's Reply-To in that case, so the answer still reaches the customer.
• Turning a group back to internal permanently removes its external members, including the RelayMail address. Allowing external members also adds an unsubscribe footer to messages sent to external members.
• Group spam handling can reject or hold messages it marks as spam, and those never reach RelayMail.

Questions