MX record specifies mail servers that handle incoming emails. If you want to use Hostinger servers to receive emails sent to your domain, you need to set Hostinger’s MX records.
Hostinger MX records are:
Value (Mail Server)
You can always see default MX records for your account by navigating to Emails → domain name → Email Delivery, just click on the arrow near MX:
Any DNS record changes trigger propagation which can take up to 24 hours to fully propagate worldwide