Every so often I can't send emails. They can sit in my outbox for hours sometimes days. I have emailed TPG support several times but have been completely ignored. When I try to send an email I get  the following message "Sender address rejected by server. Server response was: Authentication Required. Select different outgoing mail server from the list below or click try again later". There is only tpg.com.au in list so I always click try again later but nothing happens for hours /days and then suddenly the mail goes through. It is really frustrating when an important email has to be sent and it just sits there.  Does anyone else have this problem and how can I fix it.  I have a Mac computer. Any advice would be appreciated ... View more