How to use the preheader personalization string in Exact Target

If you want to use a preheader in your Exact Target email send (you should), then you’ll attempt to implement the %%_PreHeader%% personalization string listed in their documentation, only to discover it’s inclusion prevents you from doing a “test send” or a “send preview”.

The solution is the following AMPScript, place this in your template:

And this in your email properties:

Note, just like your unsubscribe and web version links, this preheader will not be rendered in a test send, but it will render in a send preview, and of course a real send.