Setting up a Microsoft 365 connector to the relay

With an outbound connector you let Microsoft 365 send all mail — or only the mail from certain domains or senders — through 2Mail. That is useful when you send large volumes from an application attached to your tenant, or when you want delivery and logging of all outgoing mail in one place. Your users notice nothing: they simply keep working from Outlook.

What to arrange beforehand

• the server name shown in your 2mail account
• every domain that will send through the connector, added as a sending domain in your 2mail account, with SPF and DKIM in order
• administrator rights on the Exchange environment of your tenant

A connector does not sign in with a username and password like a mail program does. So let us know in advance which domains will go through the connector, so we can prepare the relay on our side. That is part of the personal follow-up every account gets.

Step 1: create the connector

In the Exchange admin center, create a new connector from Microsoft 365 to a partner organisation. Give it a recognisable name and do not switch it on yet: first configure, then test, then activate.

Step 2: decide which mail goes through it

Choose whether the connector should handle all outgoing mail or only the mail selected by a transport rule. With a transport rule you can, for example, send only the mail from your invoicing system or from one sender address through 2Mail and leave ordinary user mail alone. Start with that: it is the safest way to test.

Step 3: the relay as the target

Choose to route the mail through a smart host and enter the server name from your 2mail account. Make TLS mandatory for the connection; our relay supports it and you do not want mail leaving unencrypted.

Step 4: validate and activate

Microsoft 365 offers to validate the connector with a test message to an external address. Do that, and then check in the 2Mail dashboard whether the message appears in the delivery log. If it is there, activate the connector.

Things to watch

• SPF — mail leaving through 2Mail must pass SPF too. Add the SPF value from your 2mail account to the existing SPF record of your domain, next to Microsoft's.
• Messages stay in the Microsoft 365 queue — the connector is active, but our side does not know your domain yet. Get in touch.
• All or nothing — a connector without a transport rule routes all outgoing mail. Be sure of that before you activate.

More about this integration on SMTP for Microsoft 365; the records you need on SPF, DKIM and DMARC.

Still stuck?

Tell us via contact which domains you want to route through the connector and which message Microsoft 365 shows. We sort it out together.