I am getting a warning message that says the pst has reached it's limit when I try to add an email to it, and won't let me add to it. This happened after I set the registry "MaxLargeFileSize" to the recommended value of 20480 ( 20 GB ). The PST file is only 3.8 GB ( 3,867,173 KB ). I checked the type of PST by looking at the properties. The format is "Personal Folders". I am stumped.