A complete email infrastructure includes sending domains with properly configured DNS records (SPF, DKIM, DMARC), an email service provider or SMTP server, and ideally dedicated IPs for high-volume sending. Using a subdomain like mail.yourdomain.com protects your primary domain's reputation while enabling separate reputation building for outreach activities.
Core Infrastructure Components
Sending Domains
Your sending domain is the "from" address recipients see. For outreach, consider using a subdomain to isolate reputation and protect your main domain from any deliverability issues.
DNS Authentication
SPF, DKIM, and DMARC records prove your emails are legitimate. SPF specifies authorized sending servers, DKIM adds cryptographic signing to each message, and DMARC defines how receiving servers handle failures.
Email Service Provider
Your ESP handles the actual sending — managing connections with receiving servers, processing bounces, and providing delivery analytics. Choose one that supports your use case and volume.
IP Addresses
Shared IPs pool reputation across multiple senders. Dedicated IPs give you full control but require warm-up — typically necessary for senders with 100K+ monthly emails.
Step-by-Step Setup
- Configure sending domain — Register a new domain or create a subdomain. Wait 30+ days before sending cold emails from it.
- Set up DNS records — Add SPF, DKIM, and DMARC records. Start DMARC in monitoring mode (
p=none) before enforcing. - Select and configure ESP — Choose a provider supporting your use case. Verify your domain and test authentication before any sends.
- Set up monitoring — Configure bounce handling, complaint feedback loops, and deliverability dashboards.
- Begin warm-up — Start with low volumes to engaged recipients and gradually increase over 4–8 weeks.
Subdomain Strategy
Separating email streams by subdomain protects your primary domain's reputation. Each stream can be monitored and managed independently:
- mail.company.com — Transactional emails (receipts, notifications, password resets)
- news.company.com — Marketing newsletters and campaigns
- outreach.company.com — Cold sales outreach
- notify.company.com — Product and system notifications
Dedicated vs. Shared IPs
| Factor | Shared IP | Dedicated IP |
|---|---|---|
| Reputation | Shared with others | 100% your own |
| Warm-up | Pre-warmed | 4–8 weeks required |
| Best for | <100K emails/month | 100K+ emails/month |
How SendroAI Handles Infrastructure
SendroAI abstracts infrastructure complexity while giving you the benefits of a professionally managed setup. The platform handles domain configuration guidance, automatic warm-up optimization, and intelligent sending distribution. Built-in monitoring tracks deliverability signals in real-time so you can act before issues escalate.