Troubleshooting Exchange integrations

Solutions for Exchange integration sync issues in Communications Mining, covering disabled mailboxes and integrations, silent sync gaps, and folder filter problems.

This page helps you diagnose Exchange integration sync issues in Communications Mining™. Start from what you can observe:

• The integration or one of its mailboxes was disabled with an error.
• No error appears anywhere, but emails are missing.

An integration or mailbox was disabled with an error

When the sync hits a persistent error, Communications Mining disables the failing part — a single mailbox where possible, or the whole integration when the credentials themselves fail — and notifies users who hold integration permissions on the project. To read the error, go to the Administration page, select the Integrations tab, and expand the disabled integration or mailbox.

Most mailbox errors include an Error details: line containing the unmodified error returned by Microsoft. This line names the underlying Microsoft error, so include it in any support ticket. Once you address the cause, re-enable the mailbox or integration.

Mailbox errors

Error	Cause and resolution
Cannot access '<mailbox>' please review the access policies that are in place. with Error details: ErrorAccessDenied: Access to OData is disabled: [RAOP] : Blocked by tenant configured AppOnly AccessPolicy settings.	The mailbox is outside your application access policy. Ask your Exchange administrator to add it to the scoped security group, confirm with Test-ApplicationAccessPolicy, then re-enable the mailbox.
Mailbox '<mailbox>' was not found. The SMTP address has no mailbox associated with it. with Error details: MailboxNotEnabledForRESTAPI: The mailbox is either inactive, soft-deleted, or is hosted on-premise.	The address exists, but it is not a mailbox the Graph API can read. Sync a licensed Exchange Online mailbox instead.
Mailbox '<mailbox>' was not found. The SMTP address has no mailbox associated with it. with Error details: ErrorInvalidUser	The address is misspelled, or the mailbox was deleted. Correct the address, or remove the mailbox from the integration.
Inbox folder was not found for mailbox '<mailbox>'	The service user or application cannot access the mailbox. Grant it read access, or check the application's permissions and access policy with your administrators.
Mailbox '<mailbox>' has encountered an unknown error with code: 403.	Exchange Online refused access without classifying why, for example an exceeded mailbox quota. Read the Error details: line and address the error it reports.
An error containing The security principal specified is already on the permission set, please remove duplicate.	The mailbox has duplicate permission entries for the same account or application. Ask your Exchange administrator to remove the duplicate.

MailboxNotEnabledForRESTAPI covers a distribution list, a mail-enabled user without a mailbox, an unlicensed account, and a mailbox still hosted on an on-premises Exchange server in a hybrid setup.

Integration errors

Each of the following errors appears under Error acquiring Microsoft Exchange access token:

Error	Cause and resolution
AADSTS7000215 or AADSTS7000222	The client secret is invalid or has expired. Create a new one, update the integration credentials, and note the expiry date — an expired secret stops ingestion until rotated.
AADSTS700016 or AADSTS7000112	The application was not found in your directory, or a tenant administrator disabled it. Confirm the client ID and tenant ID, and check the application in the Azure portal.
AADSTS50076, AADSTS50079, or AADSTS53003	Multifactor authentication or a conditional access policy blocks sign-in for the account. Ask your identity administrators to exclude it, or switch to application authentication.
A message about consumption or quota limits	Your organization reached its consumption or upload quota. Review your license usage, then re-enable the integration.

No error is shown, but emails are missing

The following are situations where the integration looks healthy but emails do not arrive, including expected behavior that can look like a fault.

Symptom	Cause and resolution
Emails stopped arriving right after you switched an integration from Exchange Web Services (EWS) to Graph.	Expected: the integration re-checks emails from the earliest point any folder reached over EWS, so a gap is followed by a catch-up period, without duplicates.
Credentials validated successfully, but no emails ever arrive.	Validate & save credentials confirms authentication only, not mailbox access. Verify each mailbox against your application access policy, and check the mailbox list for disabled entries.
A folder you expect is not synced, and no error is shown.	Folder filters match literal text against the full folder path, and a path that matches nothing is ignored silently. Check the prefix, spelling, capitalization, and trailing spaces.
Folder filters that work in one mailbox do not work in another.	Folder paths use the language of the mailbox, not of the user, so both the prefix and the folder names are localized. Use the mailbox's own folder names.
More folders sync than you expected.	Allowing a folder also syncs its subfolders, and a mailbox with no allowed-folder filter syncs everything, including Archive and Recoverable Items. A denied folder overrides an allowed parent.
Specific emails are missing even though their folder is synced.	A denied participant, domain, or organization matches the sender and all recipients, including Cc and Bcc. Deny the Sent Items folder rather than your own domain.
A mailbox shows no emails, but no error either.	The most common cause is an incomplete folder path. An allowed-folder list denies everything it does not match, so a single mistyped entry stops the whole mailbox.
The first sync seems slow.	The mailbox starts syncing within minutes; catching up on history takes longer, in proportion to the email after your start timestamp. Use a recent start timestamp.

Folder paths must start with root/Top of Information Store/, and that prefix is localized on a non-English mailbox — for example root/Oberste Ebene des Informationsspeichers/ on a German one.

To confirm whether a filter is the cause, temporarily remove the allowed-folder filter and check whether the mailbox syncs without it. A mailbox that is genuinely empty, or whose filters match no emails, polls successfully and reports nothing: that is a healthy state rather than a failure.

For what to expect when you switch an existing integration to Graph, check the EWS to Microsoft Graph API migration guide. If your issue is not listed, submit a UiPath® Support ticket.