We’re continually updating Perform Zone’s email systems to ensure that your emails are not caught in spam filters.
Gmail has a filter that records the behaviour of other Gmail users, such as many people reporting spam from a particular sender. This one we can’t get past.
You can see how spammy your email content is by running a spam check, this is a handy site : http://www.emailspamtest.com/run-spam-test.aspx
There are some more anti-spam tools in the setting up email section of this manual that your IT person can follow.