Outlook - .pst- & .zdb-files

It is possible to store and save mails, kalender entries, notes etc. in a so called .pst (personal store) file from your mailserver to save them local on your machine.
But in general we recommend not to work with a .pst file.

Although there are useful purposes to use a .pst file, e.g. if Outlook is appreciable slow due to a massive mail overload and claims way to much systemressources. But today this case should be really rare.
(In such a case it is rather recommended to comprimize your .zdb file in order to improve your performance. More in our Outlook Zimbra FAQ -> 'Are there any recommendations for really big mailboxes?'.

Storage location of the .pst file

As a saving location for such a .pst file we explicity recommend to chose a path which is included in our central, nightly backup, e.g. your windows home directory (H:). A second aspect you need to consider is that only you have exclusive accessrights to this path to avoid that any third person can access your personal .pst file which usually contains personal mails and confidential information.
Please take notice that the nightly backup can only access your .pst file if it is not in use. If your Outlook needs to run during nighttime you should hang out your .pst file in order that the backup can access it.

In the past there was a recommendation to use a .pst file to help to reliev the mailserver due to a serverside capacity limitations. Both of these informations are now out of date.

Negative aspects

There are also a few negative aspects which are connected with using a .pst file:
One of them is that .pst files are not cross-plattform compatible, with our Zimbra Web-Client (https://mail.desy.de) it is not possible to hang in a .pst file and access their information. The same problem occurs as well with other clients, which cannot access the .pst file permanently or simply cannot access, e.g. the windows home directory as a recommended storage location. In addition it is also possible that a to Outlook connected .pst can influence the performance of your machine negatively.

ZDB file

If you use Outlook in connection with the Zimbra Connector a so called .zdb (zimbra database) file will be created automatically, which is compareable with the previous .pst file. The file includes all mails in your inbox and grows continously with every incoming mail.And is by default located under C:\Users\ACCOUNTNAME\AppData\Local\Microsoft\Outlook on your local harddisk.
Please make always sure to keep enough space on your harddisk to avoid any problems with can may occur.