How to Compress PST Files to Avoid Outlook Errors?

[Client Thomaswilson081]

I am currently facing frequent Outlook errors and slow performance due to an oversized PST file. My mailbox size has grown significantly over time, and Outlook often shows warnings, crashes unexpectedly, or fails to sync properly. I have already deleted unnecessary emails and attachments, but the PST file size has not reduced, and errors still occur. I want to know the correct and safe way to compress PST files so that Outlook runs smoothly without risking data loss.