Stellar Data Recovery Knowledge Base (KB) Articles 790

SKB1069

Too many concurrent connections opened

Sometimes while migrating public folders to Microsoft Office 365, you get the “Too many concurrent connection opened” error. This error occurs when the public folder receives too many requests because the server of Microsoft 365 is unable to process multiple requests. To resolve this issue, you need to start the migration job again for the failed items. ..

Date Published 31 Jan 2025

Total Views 717

SKB1096

How to Extend Microsoft Entra ID Access Token Period?

The Microsoft access token lifetime policy is applicable on global tenant or organization. The current maximum Access Token lifetime is 24 hours. Create policy: Step1: Open Windows PowerShell as Administrator Step2: Install Microsoft Graph (if not already installed) Install-Module Microsoft.Graph -Scope Currentuser Step3: Connect to Microsoft Graph with required sc..

Date Published 15 Jul 2025

Total Views 635

SKB1087

How to Migrate Public Folder from Exchange to Office 365

If you want to migrate public folders from Exchange server to the public folders Office 365 using Stellar Migrator for Exchange, you will have to create a separate job. This is necessary because the software will migrate Emails and archives together but not public folders. Steps to migrate public folders from Exchange server to Microsoft 365 using Stellar Migrator for Exchange Download and ru..

Date Published 01 May 2025

Total Views 581

SKB1086

How to Migrate from Office 365 to Exchange using Stellar Migrator for Exchange?

You can use Stellar Migrator for Exchange to Migrate mailboxes from Microsoft 365 to an on premise Exchange server. This software will directly access the mailboxes on the cloud-based server and migrate them to the source server. Steps to migrate mailboxes from Microsoft 365 to Exchange server using Stellar Migrator for Exchange Download and open Stellar Migrator for Exchange. From the Log..

Date Published 25 Apr 2025

Total Views 521

SKB1095

How to Resolve: "The mailbox database is temporarily unavailable" Error?

While attempting to migrate a mailbox in Exchange, you may encounter the following error: "The mailbox database is temporarily unavailable." Cause This error typically occurs when the mailbox database that hosts the user's mailbox is dismounted. Migration cannot proceed if the database is not mounted and accessible. Resolution To resolve this issue, mount the dismounted mailbo..

Date Published 04 Jul 2025

Total Views 519

SKB1093

How to Resolve: "There are no public folder servers available" Error During Public Folder Migration?

During a public folder migration or when attempting to access public folders in Exchange, the following error may appear: "There are no public folder servers available." This error typically occurs when no public folder mailbox exists in the environment. Public folders require at least one public folder mailbox to be present and active. Without it, Exchange cannot mount or access the publi..

Date Published 04 Jul 2025

Total Views 484

SKB1094

How to Resolve "The Specified Folder Could Not Be Found in the Store" Error?

When attempting to migrate archive mailboxes, you may encounter the following error: "The specified folder could not be found in the store." This error typically occurs when the archive mailbox for a user is not enabled before the migration is initiated. Migration operations expect the archive mailbox to exist, and if it does not, the folder structure referenced during the migration proces..

Date Published 04 Jul 2025

Total Views 476

SKB1107

How to Resolve "The SMTP address has no mailbox associated with it" Error?

Cause: The error indicates that the specified folder (usually the primary mailbox) is missing or not accessible. Most often, this happens because the primary mailbox is not available for the affected user account. Resolution: For Exchange Server (On-Premises): kindly check the Primary Mailbox for the user via the Exchange Admin Center (EAC): Steps to check Primary Mailbox in Exc..

Date Published 19 Dec 2025

Total Views 469

SKB1102

Troubleshooting the ‘Mailbox does not exist’ Error

Problem Description You are unable to start migration jobs or perform actions that require connecting to your Microsoft 365 (Office 365) tenant using Stellar Migrator for Exchange. The software displays one of the following (or similar) error messages: Mailbox does not exist This error prevents successful authentication and migration operations. Root Cause The Microsoft 365 admin account ..

Date Published 19 Dec 2025

Total Views 435

SKB1103

How to resolve "Mailbox Database Temporarily Unavailable" Error

The mailbox database is temporarily unavailable., Cannot open mailbox…”with details like: .Server = SN6PR06MB4621.namprd06.prod.outlook.com .mdbGuid = ... .mailboxGuid = ... It means that Exchange Online temporarily locked or offloaded the mailbox database associated with that mailbox. This usually happens due to throttling, load balancing, or too many concurrent connections hitting the mail..

Date Published 19 Dec 2025

Total Views 414