How do I apply a campaign template before the signature template?

Policy types are always processed in the same sequence, as illustrated below:

This means that signature content is added first, then campaign content, then disclaimer content. Although you cannot change this sequence, you can swap content in policies so that your signature, campaign and disclaimers appear in a different order.

For example, if you wish to include a campaign image before a signature, you could associate a campaign template with a signature policy and a signature template with a campaign policy. This principle applies to any of the Outlook signature policies (signature, campaign and disclaimer).

For further information about how policies are processed, see understanding how policies are processed.