Microsoft Dynamics CRM has recently been displaying unreliability in its handling of Email, there has been several issues seen, these are:
• Emails stuck in “Pending Send” that never send.
• Emails stuck in “Pending Send” that never send and finally mark as failed.
• Emails stuck in “Pending Send” that have actually sent, on some occasions have sent multiple times.
• Multiple Copies of the same Email sent from CRM in the “Drafts” folder of the mailbox sending the email – Both Individual Mailbox and Shared Mailbox.
Infrastructure Overview
Microsoft Dynamics CRM 2016 (v8.1) On-Premise
Microsoft Exchange Server Online E5
These 2 are connected via Microsoft CRM Exchange Hybrid Connector – Configured as per https://docs.microsoft.com/en-us/dynamics365/customerengagement/on-premises/deploy/connect-dynamics-365-on-premises-exchange-online
NOTE: This setup has been in place for some time and no CRM modifications have been made recently, However Exchange Online has been subject to changes via Microsoft’s Own Policy.
Investigation To Date
OA Systems have investigated the issue from the CRM server side of things by looking at and diagnosing the following areas:
• Crm Server Event Logs – No Issues related to Outbound Mail Found.
• Crm Email Entity – No identifiable patterns for the issue found.
• Crm Email Entity – Delivery Attempts are sporadic and range between 1 retry to 80+ retries
• Crm Emails with the same content, sender and recipient will result in different outcomes, Sent and Failed, even when sent within 2 minutes of each other.
• On a day that we monitored and observed as only sending 400 emails in total for the day, issues with sending was still apparent with the same cause of “SenderExceededSubmissionRateLimit” (see below)
Careerforce have investigated the Exchange logs for some of the emails sent from CRM and have uncovered an issue where Exchange is throttling the mail submissions:
S:MailboxDatabaseGuid=f6e5dc2d-fb66-41a7-96aa-f2ea9eced0e9;
S:MapiNotifyTime=2020-03-04T20:16:28.299Z;
S:TenantEopForest=APC01;
S:DeliveryPriority=Low;
S:PrioritizationReason=SenderExceededSubmissionRateLimit;
S:AccountForest=AUSPR01A005.PROD.OUTLOOK.COM
So far the sending seems to have stabilised, but why was the Submission Rate Limit exceeded? The Hybrid exchange connector is using EWS not SMTP.
Question: Does EWS count towards the Submission Rate? Is the Submission rate count based on Connections or Transmissions (Successful/Failed) of emails?
• Emails stuck in “Pending Send” that never send.
• Emails stuck in “Pending Send” that never send and finally mark as failed.
• Emails stuck in “Pending Send” that have actually sent, on some occasions have sent multiple times.
• Multiple Copies of the same Email sent from CRM in the “Drafts” folder of the mailbox sending the email – Both Individual Mailbox and Shared Mailbox.
Infrastructure Overview
Microsoft Dynamics CRM 2016 (v8.1) On-Premise
Microsoft Exchange Server Online E5
These 2 are connected via Microsoft CRM Exchange Hybrid Connector – Configured as per https://docs.microsoft.com/en-us/dynamics365/customerengagement/on-premises/deploy/connect-dynamics-365-on-premises-exchange-online
NOTE: This setup has been in place for some time and no CRM modifications have been made recently, However Exchange Online has been subject to changes via Microsoft’s Own Policy.
Investigation To Date
OA Systems have investigated the issue from the CRM server side of things by looking at and diagnosing the following areas:
• Crm Server Event Logs – No Issues related to Outbound Mail Found.
• Crm Email Entity – No identifiable patterns for the issue found.
• Crm Email Entity – Delivery Attempts are sporadic and range between 1 retry to 80+ retries
• Crm Emails with the same content, sender and recipient will result in different outcomes, Sent and Failed, even when sent within 2 minutes of each other.
• On a day that we monitored and observed as only sending 400 emails in total for the day, issues with sending was still apparent with the same cause of “SenderExceededSubmissionRateLimit” (see below)
Careerforce have investigated the Exchange logs for some of the emails sent from CRM and have uncovered an issue where Exchange is throttling the mail submissions:
S:MailboxDatabaseGuid=f6e5dc2d-fb66-41a7-96aa-f2ea9eced0e9;
S:MapiNotifyTime=2020-03-04T20:16:28.299Z;
S:TenantEopForest=APC01;
S:DeliveryPriority=Low;
S:PrioritizationReason=SenderExceededSubmissionRateLimit;
S:AccountForest=AUSPR01A005.PROD.OUTLOOK.COM
So far the sending seems to have stabilised, but why was the Submission Rate Limit exceeded? The Hybrid exchange connector is using EWS not SMTP.
Question: Does EWS count towards the Submission Rate? Is the Submission rate count based on Connections or Transmissions (Successful/Failed) of emails?