Top 3 reasons why PST’s are not supported on over a network:
1. All operations take longer.
2. Write operations can take approximately four times longer than read operations.
3. Outlook has slower performance than the Exchange Client.
The .pst files are not meant to be a long-term, continuous-use method of storing messages in an enterprise environment. Two alternatives are suggested:
1. Using .ost files
2.Microsoft Windows Terminal Services.