I'm having trouble sending a mass email to all my customers that have not placed an order (around 350 customers).

I get this error:


Email Error: Could not instantiate mail function. Please check Admin->Configuration->Email Options->Email Transport.

I am using PHP as my email transport... what is really weird: I have three test accounts on my site, two using gmail email accounts and one using a yahoo. The yahoo email account recieved the email, the gmail accounts did not.

Weirder still.. when I isolate one of those accounts and send it as a single email, it goes through just fine!

*cries*