Zimbra PST Import Wizard

The Zimbra PST Migration Wizard is a tool provided by Zimbra specifically for importing PST file data directly into a mailbox on the server. This is the only supported method for migrating PST file datado not drag and drop or use the Outlook import tool. The Zimbra wizard supports importing of:

  • emails
  • calendar items
  • contacts
  • tasks

PST Preparation

Often, PST files started life in an early version of Outlook and have been through various Outlook upgrades and contain years worth of content without the benefit of any housekeeping or reorganisation. The old adage of “garbage in, garbage out” applies here – if possible seek user consent to tidy up the PST file prior to migration or have the user perform this task themselves – it will help the migration run more smoothly and it will make the users’ lives easier in the long run as their data will be better organised.

  • Make a backup of the PST file before continuing
  • If the user is happy to allow you to clean up the PST file, consider deleting unneeded large emails or folders – sort each folder by size and review for joke attachments, movies etc., empty the trash and junk folders. Consolidate multiple contacts and calendar folders and dedupe the contacts
  • Open the PST file in Outlook and use the Outlook export facility (File > Export) to create a new PST file – doing this will clean up any inconsistencies and make the import wizard’s job much easier. This is particularly important if the pst file has undergone a number of Outlook upgrades.
  • Use SCANPST.EXE to repair your PST beforehand to clean up any problems with your PST before you import. You can find SCANPST.EXE by searching for it in Windows ((START => Search => For files or folders)). For an en-US Outlook 2003 installation it should be located under c:program filescommon filessystemmsmapi1033.

Message Size Restrictions

By default, the migration tools have a local 10MB limit on the encoded size of uploaded messages. Do not confuse this encoded size with Outlook’s reported attachment size. A file with an 8MB attachment will encode to an email over 10MB, and will therefore not be imported. A 12MB attachment = 16MB encoded, a 14MB attachment = 19MB encoded.

The 10MB limit can be adjusted by adding a registry key to the Windows machine running the Import Wizard. The key/value is:


You can adjust this using RegEdit (Start -> Run -> regedit). Add a key called HKEY_CURRENT_USERSoftwareZimbra. Then add a DWORD Value called MaxAttachSizeMB and assign it a value (in MB obviously; e.g 15 = 15MB). The next time the Import Wizard runs, it will use this value.

The Zimbra server has a limit of 50MB for a complete mime-encoded messages.

Downloading and running the Wizard

  1. Download the latest version of the PST Import Wizard from the control panel – look in the Zimbra Downloads section under Support and Resources.
  2. Run the wizard from a computer with Outlook 2003, 2007 or 2010 installed and follow the on screen prompts which are self explanatory.
  3. NB – If you enter the details of a Domain Administrator on the first screen, un-tick the check box marked “Import into Account” on the second screen (just below where you provide the path to the PST file you’ll be importing).

Related Links:

Zimbra Outlook PST Import Wizard Tips