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Service | Customer Service, Contact Center, Fie...
Suggested Answer

Mailbox Email configuration

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Posted on by

Hello,
So i have been trying to enable and test my mailbox for outgoing emails

i Keep getting this errors
'

An unknown error occurred while sending the email message "Your mailbox is now connected to Dynamics 365" through the mailbox Fixit. The owner of the associated email server profile Microsoft Exchange Online has been notified. The system will try to send the message again later.
Email Server Error Code: ErrorNonExistentMailbox. Exchange.server returned 404 error.

'

Please can anyone help with a solution for this.

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  • Suggested answer
    Nya Profile Picture
    29,060 on at

    Hi,

    Please refer to the following KB article.

    "Mailbox doesn't have a valid email address" error occurs when using Server-Side Synchronization (microsoft.com)

    Cause

    This error can occur for one of the following reasons:

    1. The mailbox for the user could not be found because the email address is not correct.

    2. The email address is for a distribution group, which is not a mailbox.

    3. The mailbox is configured to use an Exchange Online profile but the user's mailbox is located in Exchange on-premises

    Resolution

    1. Verify the e-mail address of the mailbox record in Dynamics 365 matches the e-mail address in Exchange. The error includes a link to the mailbox record in Dynamics 365. You can use this link to quickly verify the Email Address field.

    2. Verify the email address is for an actual mailbox and not a distribution group.  Distribution groups are not mailboxes that store email.  Distribution groups are used to distribute emails to the mailboxes that are members of the group. 

    3. If the user's mailbox is located in Exchange on-premises, make sure you are using an Exchange Server (Hybrid) profile in Dynamics 365 instead of an Exchange Online profile.

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