Microsoft Technical Bulletins

The latest updates for all the Microsoft Products you use every day.

Written by admin

Categories: Microsoft 365

July 6, 2021

Blog Home

New outbound relay pool

QuixTec provides technical bulletins ‘unaltered’ from Microsoft. As an authorized Microsoft Partner, experienced SharePoint development group and Office 365 expert, QuixTec’s’ custom online or on premises solutions include the latest Microsoft updates throughout initiatives that we custom develop for you.

From Microsoft Corporation
Technical Bulletin:  
MC266466 · Published Jul 2, 2021

Message Summary

We’re making some changes to harden the configuration for relaying or forwarding email through Office 365.

Starting July 27, 2021, we are updating special relay pools, a separate IP address pool that is used for relayed or forwarded mails that are sent from domains that are not a part of accepted domains in your tenant. Only messages that are sent from domains that are not accepted domains in your tenant are impacted by this change.

How this will affect your organization:

When this change is implemented, messages that do not meet the below criteria will route through the Relay Pool and the messages might potentially end up in recipient junk folder.

  1. Outbound sender domain is an accepted domain of the tenant.
  2. SPF passes when the message comes to M365.
  3. DKIM on the sender domain passes when the message comes to M365.

All messages that meet the above criteria will not be relayed through the Relay Pool. For relayed messages, we will skip SRS rewrite.

What you can do to prepare:

When this change takes effect, you can tell a message was sent via the Relay Pool by looking at the outbound server IP (all Relay Pool IPs will be in the 40.95.0.0/16 range), or by looking at the outbound server name (will have “rly” in the name).

For the messages to go through the regular pool you will need to make sure when a message arrives to Microsoft Office 365, SPF or DKIM passes, or sender domain of the outbound message matches an accepted domain of your tenant

For DKIM to work, make sure you enable DKIM for sending domain for example fabrikam.com is part of contoso.com accepted domains, if the sending address is sender@fabrikam.com, the DKIM needs to be enabled for fabrikam.com. you can read on how to enable DKIM here.

To add custom domains follow the steps outlined here.

ABOUT US: QuixTec, LLC is a U.S. certified Veteran Owned, modern DevOps organization and Microsoft Partner that specializes in Microsoft SharePoint, Office 365 expertise & HTML5 technologies for small to enterprise-sized organizations. The founder, Richard, has 30 years of experience working with several notable companies that include World Vision, Expedia, Microsoft, Levi Strauss, NASA, Boeing Aerospace, Los Alamos National Laboratory, and the U.S. Air Force, to name a few.  QuixTec is in the Seattle area. Phone today for a free consultation and project estimate: (425) 367-9025    SHAREPOINT DEVELOPMENTCUSTOM SOLUTION DEVELOPMENTOFFICE 365 EXPERTSSHAREPOINT DOCUMENT LIBRARIESSHAREPOINT CONSULTANCYSPECIAL NGO RATES

You May Also Like…

Meeting Join Custom Branding

Meeting Join Custom Branding

QuixTec provides technical bulletins 'unaltered' from Microsoft. As an authorized Microsoft Partner, experienced SharePoint development group and Office 365 expert, QuixTec's' custom online or on premises solutions include the latest...