Great tip! You can also attach the resume and cover letter you used to apply to the email (assuming you customise both per application - which if you're not, you should be).

Personally I use a version of this to manage my own job applications and recommend dumping it all in your <cloud file storage solution of choice>. Each application gets a new folder (organised by year of application) with a copy of the PD (incl. salary, etc.), CV, and cover letter used to apply.

Makes it super easy to apply for similar jobs in the future too, just make a copy of the old application and update with different key words.