I read the phrases ASAP or URGENT quite often. In ticketing or issue tracking systems, in chats or also in emails. In emails they are usually accompanied with the High Importance flag.
To tell the truth to all the project managers out there - adding this kind of metadata to your issue won’t help you to get your issue solved faster.
It will just lead to the following:
1. One will read your request, evaluate the issue and prioritize it accordingly among the other issues he or she has on the to-do list.
2. If you managed to build a solid record of marking EVERYTHING as important, then you will always go last on the to-do list.
It is not rude to use ASAP or to ask for immediate help if deadlines are approaching or the business is stuck because of the issue.
But if you constantly overemphasize your issues it just shows one thing - you don’t know how to prioritize properly.
Furthermore - If your issue is that urgent, pick up the phone and give the person a call. People do check their email regularly, so as long as the subject line catches their attention, you are likely to get help soon.
Instead of flagging the mail with ASAP or High Importance use a subject line like: “Customer needs answer today” - It perfectly describes the deadline without setting a rude or desperate tone.