Send a Microsoft 365 distribution list (support@) to a Slack channel

Steps

1. 1

   Add RelayMail as a mail contact

   In the Exchange admin center go to Recipients > Contacts and click Add a mail contact. Enter a display name (for example RelayMail), an alias, and the forwarding address from your RelayMail setup page (inbox-...@relay.relaymail.app) as the email, then click Create.

2. 2

   Create the distribution list, or open the existing one

   In the Microsoft 365 admin center select Show all > Teams and groups > Active teams and groups, then the Distribution list tab. To create one, select Add a distribution list, give it a name, assign owners and members, and on Edit settings enter support@ as the group email address.

3. 3

   Let customers email it

   On the same Edit settings page, select Allow people outside of my organization to send email to this Distribution group. Without it, customers cannot reach support@.

4. 4

   Add the RelayMail contact as a member

   Open the list, go to the Members tab, select View all and manage members, then Add members. Search for the RelayMail contact, select it and click Add. Keep your teammates as members too if they should still get each email.

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

Microsoft's docs describe no confirmation email for a new member: the list delivers to the contact as soon as it is added. If one does arrive, RelayMail passes it on to the email on your Slack account until forwarding is confirmed. 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

• An outside address cannot be added to the list directly; it has to exist as a mail contact first.
• If external customers get bounces, check that Allow people outside of my organization to send email to this Distribution group is selected.
• Every member gets a copy, so the team can keep reading support@ in Outlook while it also lands in Slack. Remove members who should only use Slack.
• Mail contacts and distribution lists need admin rights in Microsoft 365; ask your admin if you cannot see these pages.

Questions