Do users need to have Manager access to their mail files?

No. Users only need to have Designer access if they are installing to their mail files themselves. If WirelessMail is installed to the mail template, users only need Editor access to use WirelessMail, but of course the person doing the installation to the template needs Designer access to the template. Users do NOT need any special agent execution privileges such as those required by the Out of Office agent that ships with the Notes mail template. Some WirelessMail features such as complete address list support and remote control require LotusScript agent execution privileges on the user's mail server for the Notes id that performs the installation.