Custom SMTP Deep Dive

Configure custom SMTP settings for email delivery.

Configuration

Environment Variables

MAIL_FROM_ADDRESS=noreply@your-company.com
MAIL_HOST=smtp.your-provider.com
MAIL_PORT=587
MAIL_USERNAME=your-smtp-username
MAIL_PASSWORD=your-smtp-password

NestJS Mailer Configuration

MailerModule.forRootAsync({
  useFactory: (config: ConfigService) => ({
    transport: {
      host: config.get("MAIL_HOST"),
      port: config.get("MAIL_PORT", 587),
      secure: config.get("MAIL_PORT") === 465,
      auth: {
        user: config.get("MAIL_USERNAME"),
        pass: config.get("MAIL_PASSWORD"),
      },
    },
    defaults: {
      from: `"${config.get("APP_NAME", "Gauzy")}" <${config.get("MAIL_FROM_ADDRESS")}>`,
    },
  }),
  inject: [ConfigService],
});

Popular SMTP Providers

Provider	Host	Port	Notes
Gmail	smtp.gmail.com	587	App password req
SendGrid	smtp.sendgrid.net	587	API key as pass
AWS SES	email-smtp.region.amazonaws.com	587	IAM credentials
Mailgun	smtp.mailgun.org	587	Domain verified
Microsoft 365	smtp.office365.com	587	Modern auth

Testing SMTP

# Test via CLI
echo "Test" | mail -s "Test" -S smtp=smtp://smtp.example.com:587 user@example.com

# Or use the Gauzy admin panel:
# Settings → Email → Test Connection

Troubleshooting

Issue	Solution
Connection timeout	Check firewall rules
Auth failed	Verify credentials, app password
TLS errors	Use port 587 with STARTTLS
Emails in spam	Configure SPF, DKIM, DMARC
Rate limiting	Use dedicated SMTP service

DNS Records

For deliverability, configure:

# SPF
v=spf1 include:_spf.google.com ~all

# DKIM
selector._domainkey.your-domain.com

# DMARC
_dmarc.your-domain.com  v=DMARC1; p=quarantine; rua=mailto:admin@your-domain.com

Related Pages

• Email Templates — templates
• Notification System — notifications
• Environment Variables — all env vars