I've been trying to resolve this issue for some time now. Basically I have Google apps handling all of my email needs and is working just fine. However, the problem lies in my WordPress installation.
My host (NameCheap.com) does not send out emails from a hosted application unless the from address is hosted on their servers. The suggested work around is to use a subdomain to send out emails but I really don't want to go about it in that manner. There have been previous posts suggesting that if you change the cPanel MX server settings to Remote Email Exchanger so that any emails are forward to the lowest MX record listed, this would resolve the issue. These posts are all around 2-3 years old and don't seem to be doing the trick for me.
Does anyone have a suggestion on how to go about resolving this issue. I'm open to using a new host but I need one that allows for unlimited subdomains for a reasonable price as I'm running a multisite installation