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Dynamics 365 Community / Forums / Customer experience | Sales, Customer Insights,... / Outlook App - Mailbox ...
Customer experience | Sales, Customer Insights,...
Suggested Answer

Outlook App - Mailbox Error 363 - Too Many Connections

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Posted on by JamesW25 50

We have been moving our 200+ users from the old CRM for Outlook Client software onto the new App.

One user is getting a Mailbox Alert inside Dynamics which says - Appointments, contacts and tasks can't be synchronised because there are too many connections to the mailbox 'username'. The owner of the associated email server profile 'profile name' has been notified. The system will try again later. Email Server Error Code: Exchange.server returned 363 error.

It has been trying again every 30 minutes for the last 24 hours but no success. The user can 'set regard' emails but not appointments.

Has anyone else had this problem before? Any ideas on how to fix it would be greatly appreciated.

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  • Suggested answer
    Mustufa Furniturewala Profile Picture
    Mustufa Furniturewala 50 on at

    Hi James,

    Hope you are doing good and thanks for reaching out through Dynamics community.

    Yes, We have seen this issue. There are 3 options to resolve this 363 exchange.server error :

    This issue occurs when there are many ACTs in a user mailbox which is trying to sync with Dynamics at a same time.

    1) If you are on Dynamics Online, Create a case and ask MS support to 'Increase/change EWS Exchange throttling policy' to 7 or more days and test/enable your mailbox within 7 days. If its Dynamics on-premise, consult your Exchange team for the same.

    2) Delete/Clear old appointments in user mailbox (Outlook) and reduce the ACT to a reasonable number

    3) Set your email server profile 'process email' or your mailbox record specific 'process email received after' field to a very recent date (like one week or less)

    Hope this helps.

    Thanks and Regards,

    Mustufa F

  • JamesW25 Profile Picture
    JamesW25 50 on at

    Hi Mustufa

    Thank you for the reply.

    Thankfully the issue resolved itself overnight on Friday night/Saturday morning. The server sync had been attempting every half an hour for about 36 hours and I can only assume that with a quieter system on a Friday night it finally had the capacity to process this user.

    The user has been with the company a long time and would have had a large amount of historical appointments and tasks.

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