.-.17857 (Customer) asked a question.
Custom email domain using O365 SMTP relay
Hi,
Has anyone tried setting up the custom email domain using the O365 SMTP relay.
The configuration needs to be of the format mail.yourcompany.com. But SMTP address in O365 has to be of the format contoso-com.mail.protection.outlook.com
Also I have to whitelist the sending IP address in O365 mail. Where can I get the list.
I have the link found here
https://help.okta.com/en/prod/Content/Topics/Security/Firewall_Whitelisting.htm
That's a big list and not all of those IP's would be used to send emails.
Regards
Nimesh
We allow mail to bounce off our O365 tenant using a connector. We don't specify the domain that can send but rather the IP. Config for one of our connectors is below. Not sure if this is what your asking...
Tablaeu - AWS
Mail flow scenario
From: Your organization's email server
To: Office 365
Description
None
Status
On
How to identify your partner organization
How to identify email sent from your email server
Identify incoming messages from your email server by verifying that the sending server's IP address is within these IP address ranges: x.x.x.x, and the sender's email address is an accepted domain for your organization.
We are not using it yet, but reading the custom email domain docs you do not relay Okta emails through your O365 tenant. The docs instruct you on how to allow Okta to send emails from our domain using Sender Policy Framework (SPF). The email originates from Okta's email servers but they use your domain as the sender. SPF is a mechanism by which other servers will determine whether SMTP relays are authorized to send email on behalf of your domain.
https://help.okta.com/en/prod/Content/Topics/Settings/Settings_Configure_A_Custom_Email_Domain.htm
I understand what you were asking now. We don't allow Okta to send emails from our domain but we do others and yes, we modify the SPF record.