Starting from August 1, Google app will only support modern browsers including current and prior major release of Chrome, Firefox, Internet Explorer and Safari on a rolling basis. According to Google blog post, “Each time a new version is released, we’ll begin supporting the update and stop supporting the third-oldest version.”
Starting from August 1, Google will discontinue support for the following browsers and their predecessors: Firefox 3.5, Internet Explorer 7, and Safari 3. In these older browsers you may have trouble using certain features in Gmail, Google Calendar, Google Talk, Google Docs and Google Sites, and eventually these apps may stop working entirely.