If you use Actionstep's SMTP servers to send mail then you need to register these IP addresses in the SPF settings of your DNS configuration to prevent your outgoing emails being marked as spam. Update your SPF or Sender-ID record to include the following:
v=spf1 a mx ptr include:_spf.actionstep.com ~all
If you already have an existing SPF record, simply amend it with:
If your SPF record contains an "~all" then make sure the addition is before the all. The "~all" should always be at the end.
Spam Settings Video