The ‘Don't add signature if already present’ option does not work if a signature template only contains an image

Relevant Product: Signature Manager Exchange Edition

Scenario

You have created a new signature template that only consists of a promotional banner image.

You have assigned the signature template to a policy and configured policy options to not append the signature content if it is already present in the email conversation:

When you test it, you notice that the policy is not applied.

Reason

The Don’t not add signature if already present option performs a plain text comparison to check if a signature has already been applied. Therefore, if the template only contains an image, there is no text to compare, it is not possible to identify if the template has already been applied.

Resolution

To avoid this behaviour, add some text to the signature template.

If required, you can format this text so the font size is small and coloured white, ensuring that it blends in with the client’s email background and that it is, therefore, invisible to the recipients.