OCI availability domains: Why sending email from different regions is a good thing

May 23, 2022 | 3 minute read
Dickie LaFlamme
Senior Deliverability Specialist
Text Size 100%:


Did you know that if you’re sending email from the United States to recipients in Germany, you incur deliverability issues immediately? Many countries around the world are skeptical of email traffic that isn’t originating from within its borders. A product of that is poor deliverability. Greylistings, deferrals, and bounces are to be expected if you’re not set up correctly to send to residents within that country.


How can you overcome this problem?

Oracle Cloud Infrastructure (OCI) availability domains are the right place to start. OCI Email Delivery has a handful of realms, and within these realms exists a multitude of regions around the world in which senders can set up their infrastructure. After an initial tenancy is set up in the corresponding realm, you can get to work on any region that represents a large part of your user base.

Because each region has its own settings and permissions, you can fine-tune the way your team manages its sending universe. You can take it a step further and get to work on creating unique sending domains to use with the infrastructure per region

For example, I send out of the Ashburn (US) tenancy with the domain example.com. A quarter of my recipient signups are from Germany. Deliverability seems to be low with a high soft bounce rate, and low engagement levels.

So, I set my tenancy to send from the Frankfurt (DE) region. I set up and customized my sending structure to reflect the region, using the following domains:

  • Sending subdomain: fr.example.com

  • Customized return path: fr.bounce.example.com

Adding my authentication of SPF and DKIM properly, I import my German-based users and start sending. Acceptance rates are much higher, and users are engaging with their mail.


Setup tips

The domain that you’re using to send to the UK might be different from the one you use within the US. Whether you decide to use your top-level domain or a subdomain to send email (example.com versus uk.example.com), we recommend setting up a custom return path to ensure that each region is associated with its categorized customized return path. For detailed instructions on how to set it up in Email Delivery, see the documentation.

Authentication measures, such as SPF and DKIM, need to be set up as well. SPF can be more broadly applied when you utilize our includes per continent, which includes many regions. DKIM is specific to the region, so create it using our self-service platform.

Ensuring that these two forms of email authentication are set up is crucial for global delivery. Countries differ in how they view authentication with some still preferring SPF-aligned with the return path domain, while others have adopted DKIM as the king of authentication

Final thoughts

While this process requires a little effort, it’s worth it in the end. Understanding your user base is key to a fundamentally sound email program. Knowing where your customers sign up is crucial to categorizing and segmenting them. By utilizing Oracle Cloud Infrastructure’s regional functionality and availability domains, your bulk or transactional email has a better shot at making it to the inbox because it originates from inside the country’s borders.

Information to start Regional Sending



Dickie LaFlamme

Senior Deliverability Specialist

A Deliverability Geek by day and avid outdoor enthusiast..also by day. I work on OCI's Deliverability team for the Email Delivery product. I have many years of experience consulting with customers about their email programs and how to effectively deliver mail.

Previous Post

Email Delivery: Cleaning up your SPF record

Dickie LaFlamme | 4 min read

Next Post

US CLOUD Act: You have questions and we have answers

Christy Thomas | 5 min read