Is it required to use DO's nameservers in my DNS settings?

Hi, so I have a domain which was purchased on Asia Registry which already has existing records which I am not allowed to touch or change except for the A record because I need to somehow point it to the DO droplet without changing the nameservers. Is this possible? Am I able to point just the A record to the droplet’s IP and let the old records still do their thing? My main concern is the mail server that is already set up which will probably go offline a bit if I change the nameservers.