I use Google Apps with my domain.
Recently, we have begun to receive spam that gets past Google's spam filters. They are from our own email addresses.
I am wondering how to prevent this kind of email spoofing.
We use an SPF record with the "~all" setting. I'm wondering if I can upgrade that to "-all". However, Google Apps recommends against it. Also, I'm not 100% sure that our SPF record is complete.
Thank you ever so much.