When you create a POP3 or IMAP account in Outlook it creates a PST file where it stores a local copy of your emails. And while you can change the location of a POP3 PST file any time you want doing so for IMAP account is a little trickier
Sometimes, however, having Microsoft to force your IMAP PST file to live in your profile folder can be inconvenient (for example if you have an SSD and space is at a premium) or in the situation I bumped into – a terminal server it could be a total show-stopper. Imagine this: you built your terminal server, you designated a nice big separate array for user data only to discover that 50 users are all storing tens of gigabytes of their emails on the c: drive and are running it out of available space.
Unfortunately Microsoft has failed to imagine such a situation and thus does not provide an easy method to rectify it. Looking on the internet I saw people using primarily 2 different methods – changing the pst path via registry or using symbolic links. As numerous people reported problems with the registry approach I used the symbolic link one.
The method is really simple, just got to make sure you type in your path and file name exactly right. The symbolic link then lives in the profile while the actual pst now lives on the data volume and consumes disk space there and not on the system volume.
A note: I would not recommend making a symbolic link to a pst that lives on a mapped drive. If for any reason the server loses the connection to that mapped drive outlook will assume the pst file has become corrupt and will create a brand new one in the default profile folder and re-download all the messages back in there.