error 0x80070002 may be due to problem in your security settings. If have recently made any changes in your AV program then verify that it is allowing you to send of receive emails. If it is okay then it is sure that your PST file have got corrupted. You should instantly repair that file using scanpst.exe tool. If you are unable to locate the file on your system under program file folders then download scanpst.exe from some authorized source and then try to solve the problem.

All the best!!!!!!!!!!!!!!!!!!!!!