Yes, using subdomains for email sending can be highly beneficial, especially for large campaigns or cold outreach. Here’s how subdomains can help, along with some best practices:
Benefits of using subdomains
- Protects primary domain reputation
- Sending high volumes of marketing or cold emails from a primary domain risks lowering its sender reputation if engagement drops or complaints increase. Using a subdomain (e.g., marketing.yourdomain.com) isolates these activities, keeping your main domain reputation secure for essential emails, like customer service or transactional messages.
- Improves deliverability control
- Subdomains allow you to build a separate reputation with email service providers (ESPs) based on the type of emails you’re sending (e.g., newsletters vs. cold outreach). ESPs treat each subdomain individually, so well-maintained subdomains can help improve deliverability for different types of campaigns.
- Organizes different email streams
- Separating transactional emails, marketing emails, and customer service emails by subdomain provides better organization and simplifies tracking engagement and performance across various email streams.
Best practices for using subdomains
- Authenticate each subdomain separately: Set up SPF, DKIM, and DMARC records for each subdomain to ensure ESPs recognize them as legitimate. This helps establish trust and improve deliverability.
- Warm up each subdomain individually: If you’re starting a new subdomain for cold emails or marketing campaigns, gradually increase sending volume to build its reputation. Using tools like Warmup Inbox can automate this process and protect deliverability.
- Monitor engagement metrics by subdomain: Track open rates, click-through rates, bounce rates, and complaints separately for each subdomain to catch any issues early and adjust as needed.
Summary:
Using subdomains for email sending helps protect your main domain’s reputation, improves deliverability control, and keeps your email streams organized. For effective cold emailing or large marketing campaigns, setting up a dedicated subdomain is a smart, reputation-safe approach.