In follow up emails, the phrase “Per my last email,” can be avoided, as it can sound a bit rude.

Just point directly at the request, by circling, pointing or directing clearly to the original request.

You can restate your original request, summarizing in one or two sentences.

If your original email was never read, this will be beneficial again.

Simply and directly asking about the request, or a question related to the request can make the respondent look at your original request and do the required work before you get a reply.

If you catch hold of the person you require follow up from, you can politely remind them about the email.

If necessary, pick up the phone and call to ask, just saying that you were about to type a follow-up email so thought of calling and asking first.

This might sound a bit intrusive but it is an effective tactic to drop by their workstation/cabin and ask about the response or action.

Whether you call, drop by or talk in the lobby, do send an email to keep a record of the discussion.