Spam issues

Most of the people using Google at our church have reported Constant Contact emails going directly into Spam. This is a change within the past month. We are not doing any of the "red flag" things that could cause this (not asking for money, no baiting, etc.). These are church newsletters! The warning that comes up in my spam folder for them says that they could not verify that the email was from who it says it's from. I imagine we are not the only organization having this issue. Is there a workaround? Have you contacted Google?