I'm using Mac Mail 4.6 to send and receive through my gmail account. This seemed to be working just fine for several years now but I recently started getting feedback from mail recipients that my email is being tagged as not coming from my gmail account. When I checked it out I found that while the incoming gmail server setup is just fine, my outgoing gmail server is "offline". This forces Mac Mail to use sonic as my outgoing mail server, posing as a response from my gmail account, which in turn looks like spam to my recipients email programs.
Why is my gmail outgoing server "offline" and how can I set it up so that Mac Mail will use gmail for both incoming and outgoing mail?