Read time 5 minutes

Summary: Dial Tone Portability provides temporary mailboxes for uninterrupted email communication during Exchange Server failures. This recovery process creates a “dial tone database.” Admins can merge it with the original mailbox after restoration. It’s complex, so consider alternative solutions like Kernel for Exchange Server, offering efficient Exchange Recovery with multiple destination options.

In straightforward terms, Dial Tone Portability refers to the provision of a temporary mailbox to users for sending and receiving emails while their original mailbox undergoes repairs or restoration. This feature is invaluable for businesses, ensuring uninterrupted email communication in the event of Exchange Server failures or database issues.

You have the option to set up a temporary mailbox on either the same server or another server within your organization, provided that these servers host databases with matching database schema versions. The Autodiscover feature seamlessly redirects clients to the new database without the need for manual intervention. As an administrator, once the user’s original mailbox has been successfully restored, you can proceed to merge the recovered mailbox with the dial tone mailbox.

Dial Tone Recovery in Exchange Server 2016/2013

In the process of Dial Tone recovery, an empty database is generated on a mailbox server, effectively replacing the failed database. This newly created empty database is referred to as a “dial tone database.” This dial tone database enables the sending and receiving of messages while the original database undergoes repair and restoration.

Performing Dial Tone Recovery

The pre-requisites for executing the Dial Tone Recovery are:

  • The user must have Organization Management permissions on mailboxes
  • Must have less number of databases on the server than the maximum allowed

Info: Exchange 2013/2016 Standard Edition supports up to five databases per server.

How to perform dial-tone recovery on a single server

Start Exchange Management Shell and run the given commands one-by-one:

  1. To create a dial tone database, run the command –
    New-MailboxDatabase -Name <dial tone database name> -EdbFilePath <enter full EDB file location path>
  2. To reset the user mailboxes hosted on the database being recovered, run –
    Get-Mailbox -Database <database name> | Set-Mailbox -Database <dial tone database name>
  3. Now, mount the database so that client computers can access the database, and send and receive the messages –
    Mount-Database -Identity <dial tone database name>
  4. Create a recovery database using this command –
    New-MailboxDatabase -Recovery -Name <recovery database name> -Server <server name>

    To create another recovery database on another server –

    New-MailboxDatabase -Recovery -Name <recovery database name> -Server <server name> -EdbFilePath “<full EDB file path location>” -LogFolderPath “<full log folder path location>”
  5. Once the data is copied to the Recovery database, copy the log files from the failed database to the recovery database log folder so they can be played against the restored database.
    First, mount the recovery database and then dismount it –

    Mount-Database -Identity <recovery database name>
    Dismount-Database -Identity <recovery database name>
  6. After dismounting the recovery database, move current database and log files residing in the recovery database folder to another secured location (it is a preparation step to swap recovered database with dial tone database).
  7. Now, dismount the dial tone database-
    Dismount-Database -Identity <dial tone database name>

    Now move database and log files from dial tone database to recovery database folder.

  8. Further, move the database and log files from the secured location to the dial tone database folder. Once moved, mount the dial tone database again –
    Mount-Database -Identity <dial tone database name>

    Now, users can access the original database and can send and receive messages.

  9. Once again mount the recovery database-
    Mount-Database -Identity <recovery database name>
  10. To export the data from the recovery database to recovered database, run the following commands-
    $mailboxes = Get-Mailbox -Database <dial tone database name>
    $mailboxes | %{ New-MailboxRestoreRequest -SourceStoreMailbox $_.ExchangeGuid -SourceDatabase <recovery database name> -TargetMailbox $_ }
  11. Now, you can dismount and remove the recovery database-
    Dismount-Database -Identity <recovery database name>
    Remove-MailboxDatabase -Identity <recovery database name>

Now to verify that your mailbox has successfully been moved, open the mailbox Microsoft Outlook and Outlook for Web and check messages.

An Easier Recovery Method

The Dial Tone recovery process is certainly functional, but its complexity might pose a challenge. Proficiency in Exchange Management Shell is also a prerequisite. Hence, a more efficient alternative would be to employ a solution that offers instantaneous Exchange Recovery. To meet this need, Kernel is pleased to introduce an exclusive solution for EDB file database recovery.

This versatile tool is meticulously engineered to proficiently repair corrupt Exchange databases while offering the flexibility to save the recovered data in various destinations such as PST files, Live Exchange, and Office 365. Additionally, it seamlessly facilitates the migration of shared mailboxes and public folders. Its integrated Backup Extractor function allows for effortless restoration of EDB files from Exchange backup archives. Remarkably, this EDB to PST Converter tool is renowned for its cutting-edge capabilities, ensuring compatibility with the latest versions of Outlook and Exchange.

You can quickly restore EDB files and directly export its mailboxes to PST without even adding any destination.
Export EDB mails to PST

Evaluate the tool yourself with its free version and enjoy quick EDB file repair and its conversion.

Kernel for Exchange Server