How to push a superior to approve a request

[firewallengineer]

Hi, I’ve a situation whereby my superior is a very busy person and he manages a lot of people under him. I’ve an urgent request and already submitted email to him asking for an approval. However, it seems like he didn’t read my email yet. I know it’s common to say like “any update to the below request” if you’re talking to your peer. The question is, what is the polite way (via email) asking him to approve my request? Please let me know if there is better idea how to do this. Thanks

[Barb_D]

Is it a personal request? Like, time off to go to a family event? Or a work-related request, something that will help a client? Or something that will make you work more efficiently? You can always just forward the original e-mail to him and ask if he has any questions or needs any additional information to make a decision, but it might help if you added explanatory information about its urgency yourself. You could also pick up the phone, you know!