Random Payslips not getting emailed

Over the last month we have had random staff not receiving there payslips, all payslips are emailed at the same time and then we get the query that a staff member has not received there payslips and we check the sent emails in MYOB and that person is not showing in the sent emails. The really wierd part of this is that it  has happened to three diferrent people in the last three weeks, I resend there payslips again through Print/Email Payslips and I have to change the filters to show sent payslips which would indicate that it has been sent and it then the staff get there payslip.

Any help would be appreciated