Organizations increasingly rely on automated email communications from platforms such as Oracle EBS and Oracle Fusion Cloud for essential business processes. Recent updates and forthcoming changes to Exchange Online introduce new outbound email limitations, specifically the (Per Mailbox) External Recipient Rate Limit (ERRL) and the Tenant External Recipient Rate Limit (TERRL).

As highlighted in the STR Software blog post “Solving Microsoft 365 Rate Limits when Sending from Oracle EBS and Oracle Fusion Cloud,” these limits can pose significant challenges for entities that generate high volumes of automated emails. This post aims to provide Oracle EBS and Fusion Cloud users with a comprehensive understanding of these evolving restrictions and to outline practical strategies for managing their automated email sending to maintain operational continuity.

Understanding the New Microsoft 365 Recipient Rate Limits: What Oracle Users Need to Know

Microsoft has implemented new measures to manage the usage and prevent abuse of Exchange Online resources, impacting how organizations send email, particularly to external recipients.

As of January 6, 2026, Microsoft has canceled the implementation of the ERRL. Microsoft’s Recipient Rate Limit and Tenant-level External Recipient Rate Limit documented in Exchange Online limits remain unchanged.

STR Software will leave this post for historical purposes only.

Potential Bottlenecks and Challenges

Hitting the Limit

The introduction of the MERRL means that all messages sent outbound to external recipients from a mailbox count against the mailbox’s quota. This includes individual senders, including shared mailboxes and mail-enabled groups (as an example, this can include email addresses such as “accounting”@domain.com and “donotreply”@domain.com).

While, the introduction of TERRL means that all messages sent outbound to external recipients from the tenant are counted against the quota.

These limits are applicable regardless of whether they originate from Exchange Online mailboxes directly, on-premises systems like Oracle EBS, or internet-connected applications like Oracle Fusion Cloud. If automated Oracle systems generate a high volume of external emails, the tenant is at risk of exceeding its daily sending limit.

If these limits or quotas are hit, emails will be blocked from sending and your senders (mailboxes) will receive Non-Delivery Receipts (NDRs) with the error code 550 5.7.233. This disruption can severely impact the timely delivery of crucial business documents.

Double-Counting

Furthermore, there is a potential risk of double-counting external-bound emails if they are routed out of Exchange Online for processing by third-party services (e.g., email signature or archiving solutions) and then routed back into Exchange Online before being sent to the final external recipient. While Microsoft acknowledges this and is investigating alternatives, it currently advises that such messages might be counted more than once against the ERRLs.

Other Considerations

It is also important to reiterate that Exchange Online is not designed to accommodate bulk-mailing scenarios. Relying solely on Exchange Online for high-volume automated emails from Oracle systems can inherently lead to these rate limitations being encountered.

Finally, misconfigurations in hybrid environments, such as certificate mismatches with on-premises gateways, can sometimes lead to external emails being incorrectly attributed to the sending tenant and thus counted against the ERRLs.

Strategies for Oracle Users to Navigate Microsoft 365 Email Limits

Proactive planning and adopting appropriate strategies are essential for Oracle EBS and Cloud users to manage the new Microsoft 365 email-sending limits effectively.

Optimizing Email Sending from Oracle Systems

• Implement batching and scheduling: Configure Oracle systems to send automated emails in batches and schedule them throughout the day to avoid large, sudden spikes in outbound volume.
• Prioritize critical communications: Identify essential automated emails and potentially delay sending less time-sensitive notifications.
• Implement monitoring and alerting: Establish mechanisms to track the volume of outbound emails from Oracle systems to proactively monitor usage against the MERRL and TERRL.
• Review and optimize email frequency: Evaluate the necessity and frequency of automated reports and notifications sent to external recipients.
• Consolidate notifications: Where feasible, consolidate multiple individual notifications into a single, more comprehensive communication to reduce the overall number of external emails.

Consider Alternatives

Consider utilizing Oracle add-ons designed to handle large-volume bulk sending. STR Software’s AventX is designed to provide a comprehensive document and report delivery solution for Oracle EBS and Oracle Fusion Cloud. One of the solution’s many benefits is the ability to send your email off of Microsoft 365, bypassing the rate limits for high-volume senders and offering more reliable delivery of critical business documents from Oracle systems.

Additionally, AventX provides advanced features such as email grouping (to consolidate messages), detailed tracking of email delivery status (bounces, spam complaints, opens, etc.), and more.

Managing Shared Mailboxes and Service Accounts

• Recognize that emails sent from shared mailboxes, email-enabled groups, and room mailboxes contribute to the ERRLs.
• Assess the volume of external emails sent from such non-licensed mailboxes.
• If high-volume sending to external recipients is necessary from a service account, consider utilizing a licensed mailbox with optimized sending patterns or exploring the use of add-ons.

Monitoring and Troubleshooting

• Regularly monitor the “Tenant Outbound External Recipients” report in the EAC to stay informed about the tenant’s TERRL usage.
• Utilize the `Get-LimitsEnforcementStatus` PowerShell cmdlet for automated monitoring of the TERRL status.
• Understand the NDR error code 550 5.7.233, which indicates that the tenant has exceeded its daily external recipient rate limit. Establish internal processes for addressing and potentially resending failed communications.

Conclusion: Planning for Sustainable Automated Email Communication

For Oracle EBS and Oracle Fusion Cloud users, a thorough understanding and proactive management of the new Microsoft 365 email limits are crucial for ensuring the smooth operation of automated business processes. By assessing current email-sending patterns, implementing optimization strategies, and considering alternatives like AventX, organizations can mitigate the risks associated with these limits and maintain effective external communication. It is essential to remain aware of the evolving nature of cloud service limitations and to continuously monitor and adapt email-sending practices accordingly.

Furthermore, exploring solutions like AventX can provide valuable additional functionality, such as insights into email delivery with detailed tracking of bounces, spam reports, and recipient engagement.

Are you a high-volume sender who relies on Microsoft 365 Exchange Server to transmit critical business documents from Oracle EBS and Oracle Cloud ERP? If so, you may have encountered a significant challenge: Microsoft 365 rate limits on email sending. Sending many emails can result in delays and disruptions, affecting the timely delivery of crucial messages—invoices, purchase orders, and more—to your recipients.

Here’s a summary of the critical limits; a full list can be viewed at the link above.

• Recipient Rate Limit: A user can send emails to a maximum of 10,000 recipients daily. If this limit is reached, sending messages will be blocked until 24 hours have passed and the number of recipients sent to drops below the limit.
• Message Rate Limit: A user can send emails at a rate of 30 messages per minute. Excess messages will be throttled and sent in the following minutes if this limit is exceeded. Exchange Online is not recommended for bulk-mailing scenarios.

Think of the email delivery process as a complex highway system. Your emails are like cars, traveling from the source (Oracle EBS or Oracle Cloud) to the destination (your recipients’ inbox). Microsoft 365 rate limits can be likened to traffic jams that slow down the flow of your emails.

Solving the Rate Limit Problem with AventX

Thankfully, there’s a solution that can put an end to these limitations and enhance your email delivery process. Introducing AventX for Oracle EBS and AventX for Oracle Cloud, featuring the powerful Email Tracking module.

AventX is designed to bypass Microsoft 365 rate limits and streamline the delivery of your emails. How does it work? The module harnesses the capabilities of AventX as an email service provider (ESP) to send emails from Oracle EBS and Oracle Cloud. As the emails are transmitted, the system captures comprehensive delivery data, providing real-time insights into the status of each email.

Most importantly, the solution does not implement any substantial rate limits to the number of emails you can send per hour or day. Thus, ensuring that your critical Invoice, Purchase Orders, and other documents are sent on time!

Revisiting the traffic jam analogy, AventX Email Tracking acts as a real-time GPS, guiding your emails around these roadblocks and providing your own dedicated route. With this powerful tool, you can avoid delays and ensure your emails reach their destination efficiently.

The Power of Real-Time Insights

Imagine having access to real-time data on the status of your critical business emails. With AventX Email Tracking, you gain full visibility into the delivery process. When an email is sent, you can monitor its journey until it reaches its destination. If, for any reason, an email is not received by the intended recipient, you will know promptly. This allows you to take swift action and ensure your messages reach their target audience without delay. And, if there is an error, you can react quickly to resolve the issue and resend the important message.

If you are a high-volume sender relying on Microsoft 365 Exchange Server to send critical business documents from Oracle EBS and Oracle Fusion Cloud, AventX is tailor-made for you. Whether you’re handling invoices, purchase orders, or other essential communications, this solution ensures the smooth transmission of your messages without being constrained by Microsoft 365 rate limits.

Say goodbye to delays and failed messages, and ensure your emails reach their intended recipients promptly. Embrace AventX Email Tracking today and witness a seamless email delivery experience like never before. Your high-volume sending process and critical business document delivery will become a streamlined highway of communication, ensuring your vital messages arrive at their destination without detours or disruptions.