I have Sparrow (MAS version) installed both at home and at work for my personal gmail account, and I use Mac Mail for the business exchange account. A few days ago I started noticing that I would delete emails in Sparrow but the emails would still show on my iPhone, and then I checked and they were also still there in gmail. This happens with Sparrow both at home and at work. I have had to drop Sparrow and go back to using the gmail web interface, but I really don't like it. I wish that Mac Mail would play nice with gmail without a complicated setup process. I enabled gmail on my Mac Mail a few days ago and noticed it was acting strange as well; perhaps Google is making changes and this is what broke Sparrow. I like to keep my personal and work emails separate. Is there any other gmail client for the Mac that works seamlessly?