Hi mummyh66xx, What is your email provider? Is it Yahoo!, Gmail, Hotmail, MSN, or possibly another provider? If your emails have disappeared from your Sent folder, it's likely that it's related to your email provider, regardless of the browser you are using to navigate. We suggest you contact the Support team of the email provider you are using, so that they can further investigate the issue and possibly recover your lost emails. Best of luck! Please let us know if you have any other questions. Thanks!! - Ralph