Microsoft Exchange replacement

Top Dog in Sight

Mobile Use

Grommunio's Mobile Device Management (MDM) is based on the features included in Microsoft Exchange. Together with grommunio Sync, it takes care of sharing and synchronizing mailboxes and enables access to shared folders depending on the user's authorization. Additionally, remote wipe is supported, with device policies per the manufacturer. Remote wipe and some other functions can be configured in the administrator panel in the web GUI without user interaction.

MDM does not have a separate app because, just like Exchange, grommunio uses the functions of Microsoft Exchange clients, which are disguised as "accounts" through provisioning in mobile devices. After setting up an account, the administrator can remotely wipe the phone. Users can also delete and reconnect, just as when using an Exchange server. The ownCloud-based grommunio Files function stores data on users' devices, enabling sharing, syncing, offline use, and many other features, including a search engine, versioning, and automatic image upload.

Data Migration

A simple definition of digital sovereignty is: "exit strategy first." Before signing a contract, IT management must answer the question of how to migrate data away from a new server product. Grommunio seems promising here with its open standards. For example, email can be read with any standards-compatible mail client. Because the groupware product is open source, server states can be tracked, data model changes can be analyzed, and actions can be initiated.

Things don't always work that seamlessly with Microsoft Exchange. Exchange admins know that, in the past, even migrating from one version to the next could be tedious and hazardous, sometimes even failing completely. Although Microsoft upgrades have certainly improved in quality and stability, migrations to third-party groupware solutions at the latest almost always rely on the physical presence of the admin in front of the client.

Scripts offered a remedy to this problem (e.g., for Microsoft PowerShell, which the grommunio developers also use as a basis). The gromox-pffimport tool has been added to their product and offers scripts for importing Exchange data by user and account. Since 2022, users benefit from the powerful PowerShell exchange2grommunio.ps1 script [10] that connects to the server and handles the migration. The script automatically creates mailboxes on the destination server and uses the plink.exe executable for secure connections, Common Internet File System (CIFS) for access, and .pst files for data migration. Administrators will have to fill in some variables in the script and then run the script from the Exchange admin shell. The script has about 500 lines, assumes a correct LDAP/AD setup (also with grommunio attached!), and requires at least Windows Server 2012 R2 and PowerShell 2.0. Listing 1 shows the first lines of the migration loop.

Listing 1

Migration by Script

01 foreach ($Mailbox in (Get-Mailbox)) {
02   $MigMBox = $Mailbox.PrimarySmtpAddress.ToString()
03   if ($IgnoreMboxes.contains($MigMBox)) {
04     $MailboxesSkipped++
05     $MailboxesTotal++
06     Write-Host "Ignoring mailbox: $MigMBox" -fore yellow
07     continue
08   }
09   Write-Host ""
11   [...]
13   Write-Host "Removing all MailboxExportRequests." -fore green
14   Get-MailboxExportRequest | Remove-MailboxExportRequest -Confirm:$false
16   # Remove old / orphaned .pst file
17   if (Test-Path -Path $WinSharedFolder\$MigMBox.pst) {
18     Remove-Item -ErrorAction SilentlyContinue -Path $WinSharedFolder\$MigMBox.pst
19     Write-Host "Removing outdated $MigMBox.pst file." -fore yellow
20   }
21   Write-Host ""
23   # Create a .pst file for every mailbox found on system.
24   #
25   Write-Host "Exporting mailbox $MigMBox to file $MigMBox.pst..." -fore green
27   [...]
29   New-MailboxExportRequest -Mailbox $Mailbox -FilePath $WinSharedFolder\$MigMBox.pst | ft -HideTableHeaders
30   Write-Host -NoNewline "[Wait] " -fore yellow
31   $MailboxesTotal++
33   [...]
35   $nTimeout = 0
36   while ((Get-MailboxExportRequest -Mailbox $Mailbox).Status -ne "Completed") {
37     Start-Sleep -s 2
38     $nTimeout += 2
39     if ($nTimeout % 60 -eq 0) {
40       Write-Host -NoNewline "|" -fore yellow
41     } else {
42       if ($nTimeout % 10 -eq 0) {
43         Write-Host -NoNewline "." -fore yellow
44       }
45     }
46   }
48   [...]

Migration Tools

So far, an alternative way to migrate data has been lacking. Like the majority of groupware products on the market, Microsoft Exchange uses its own formats to store user data such as mailboxes, calendar entries, and contacts. To exchange information between different instances in a better way, it does let you export files to compatible formats. Grommunio uses a similar approach to import user data exported from Exchange into its user database Gromox.

The grommunio developers are aware of the importance of a migration tool, especially given their ambitious claim of being able to act as a drop-in replacement for Exchange. Grommunio supports the Microsoft PST (Outlook data file), OST (offline Outlook data file), and PAB (personal address book) formats and integrates the open source imapsync IMAP transfer tool and fetchmail. Both are used to import data from other servers. A server-side migration tool is already under development.

Buy this article as PDF

Express-Checkout as PDF
Price $2.95
(incl. VAT)

Buy ADMIN Magazine

Get it on Google Play

US / Canada

Get it on Google Play

UK / Australia

Related content

  • New Exchange standard
    Service Pack 1 for Exchange 2013 introduced a new protocol, which has become the default in Exchange 2016: MAPI over HTTP.
  • Changes in Exchange Server 2013
    Exchange Server 2013 sees Microsoft complete the latest version of its groupware solution. In this article, we introduce new features in the server and reveal which features have been eliminated.
  • Exchange Web Services for Mailbox Access
    Exchange Web Services (EWS) is an important interface that lets applications access Exchange content. You can access the EWS mailbox via PowerShell or create your own tools.
  • Exchange Online migration with the Hybrid Agent
    Exchange's Hybrid Agent takes the complexity out of migrating from a local Exchange environment to Exchange Online.
  • Exchange Server through 2025
    The next generation of Exchange 2019 was announced for the second half of 2021, but the release plan was revoked in 2022, and the next Exchange was postponed until 2025. We take an in-depth look at the current timetable.
comments powered by Disqus
Subscribe to our ADMIN Newsletters
Subscribe to our Linux Newsletters
Find Linux and Open Source Jobs

Support Our Work

ADMIN content is made possible with support from readers like you. Please consider contributing when you've found an article to be beneficial.

Learn More”>


		<div class=