How do I solve iproblem in office XP as i am not able open PST file

hi Experts,

i have a problem in office Xp installed in my machine.i created a pst file for the year 2007 and all the mails are kept in the file.yesterday i sent a bulk mail which contains 121MB size. i sent the mail at 4:00 clock i got the reply from our proxy server as a failure error sub-system.After i got the message i am not able open the mail we are running a mail server with Qmail.i tried by copying the PST into other machines to delete the particular file no luck has happened.just help to sort the prob its important as all the mails kept in that PST.

Any help its would be really appreciated.

Thanks & Regards,
Allabux.A