The phrase "as soon as possible" is widely used in casual business conversation. If you were speaking (officially or semi-formally), you would say "as soon as feasible" rather than just "ASAP." If you're sending an email to someone with whom you don't have a more informal connection, it's best to type out the sentence. Otherwise, your message may be interpreted as rude and dismissive. For example: "As soon as feasible, we need to discuss the status of this project." Or: "I understand that this will cause some delay, but as soon as ASAP we need to get started." Using these phrases in emails to colleagues and customers can make them seem less demanding and avoid causing additional delays for other projects or tasks.