Migration Timeout

Question

Hello, I have 3 user mailboxes Tha I am unable to complete their migration from on-prem to the 365 Cloud. I receive the following error. I was wondering if I could get some help with this:

The call to 'https://mrsproxy.svc' timed out. Error details: The request channel timed out attempting to send after 00:00:07.8886831. Increase the timeout value passed to the call to Request or increase the SendTimeout value on the Binding. The time allotted to this operation may have been a portion of a longer timeout. --> The HTTP request to 'https://EWS/mrsproxy.svc' has exceeded the allotted timeout of 00:00:07.8886831. The time allotted to this operation may have been a portion of a longer timeout. --> The request channel timed out attempting to send after 00:00:07.8886831. Increase the timeout value passed to the call to Request or increase the SendTimeout value on the Binding. The time allotted to this operation may have been a portion of a longer timeout. --> The HTTP request to 'https:///mrsproxy.svc' has exceeded the allotted timeout of 00:00:07.8886831. The time allotted to this operation may have been a portion of a longer timeout.

Answer 1

Hi @MIS 

Thank you for reaching out to Microsoft Learn Q&A!    
Based on your description, I understand that you're unable to complete the migration from your on-premises Exchange environment to Microsoft 365 due to a "timeout exceeded" error. 

As forum moderators, we don’t have access to a dedicated testing environment to replicate specific user scenarios. However, we’re committed to providing accurate support based on the resources available to us. To better understand your situation, I’d like to clarify some points: 

Question 1:  When you mentioned that three user mailboxes are failing during migration, does this mean other mailboxes were successfully migrated, or are these the only mailboxes included in the current migration batch? 

Question 2: What version of Exchange Server are you currently using?
 

Additionally, here are some key conditions required for a successful migration: 

• TLS 1.2 must be enabled as the minimum required version. 
• MRSProxy should be enabled and running. 
• Exchange Online requires Negotiate (NTLM) authentication for MRSProxy. 
• On-premises migration Admin needs to have the minimum required permissions and valid credentials. 

I found an official Microsoft support article that may help. One possible cause of this error is a mismatch between the ExchangeGUID of the Exchange Online MailUser object and the on-premises mailbox. You can refer to the solution in this article: “The remote server returned an Error 404” or "HTTP request has exceeded the allotted timeout" error when you move a mailbox from on-premises Exchange Server to Exchange Online - Microsoft Support 

Furthermore, other users have reported similar issues caused by internet restrictions. Please double-check your firewall, load balancer (if applicable), or other network configurations that might affect connectivity. 

After reviewing the above, you can also run the Test-MigrationServerAvailability cmdlet to verify whether the error message returned matches the one encountered during migration. 

Please know that while our initial response might not resolve the issue right away, your input is incredibly valuable. With a bit more detail, we’ll work together to find the best solution for you.  

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Answer 2

Good morning, this is the first time I am having this issue. The previous migrations went through just fine. It seems to me that for some reason I lost connection between the 0365 to my on prem.