How would you implement a Cron Job that can send A lot of emails at once in NEST JS - cron

Question

I need to Implement a Cron Job that runs once a day and check if a user meets the requirements, the thing is that the platform this will be implemented in has already 3000+ users, I am Using AWS SES and NODEMAILER,
This is my mailer config
transport: {
pool: true,
rateDelta: 1000,
rateLimit: 13,
socketTimeout: 10000,
maxConnections: 5,
maxMessages: 100,
host: process.env.SMTP_MAIL_HOST,
port: parseInt(process.env.SMTP_MAIL_PORT),
secure: false, // upgrade later with STARTTLS
auth: {
user: process.env.SMTP_MAIL_USER,
pass: process.env.SMTP_MAIL_PASS,
},
},
and this is my Cron Job
// Every day at 12:00:00 America/Atikokan (EST)
#Cron('0 0 18 * * *', {
name: 'ReferralsPromo',
timeZone: 'America/Atikokan', // <-- EST
})
async handleCron() {
this.logger.log('Referral Cron job executed');
const candidates =
await this.candidatesService.FindReferralPromoCandidates();
this.logger.log(`Found ${candidates.length} candidates`);
candidates.forEach(async (candidate) => {
try {
if (condition) {
const data =
await this.referralUniqueIdService.getCandidateUniqueReferralId(
candidate.User.Email,
);
const { UniqueId } = data;
this.mailService.sendReferralPromoteEmail(candidate.User, UniqueId);
this.candidatesService.updateCandidateReferralPromo(candidate.Id);
}
} catch (error) {
this.logger.error(error);
}
});
}
I would really appreciate some advice