How to set up a cold email domain (secondary domains + redirects)
Never send cold email from your primary domain. Buy a few lookalike secondary domains, 301-redirect them to your main site, set up SPF/DKIM/DMARC, and warm them. Here's the full setup.
Short answer: setting up a cold email domain starts with one rule — never send from your primary domain. Buy a few lookalike secondary domains (e.g. try-acme.com, getacme.io), 301-redirect them to your main site, configure SPF + DKIM + DMARC on each, add a couple of warmed mailboxes per domain, and warm them for ~3 weeks. Your primary domain's reputation stays protected while you spread volume across several throwaways.
The setup, step by step
- Buy 2–4 secondary domains that resemble your brand.
- 301-redirect each to your primary site (so clicks/lookups land somewhere real).
- Authenticate each: SPF, DKIM, DMARC (start
p=none). - Add 1–3 mailboxes per domain (Google/Microsoft/SMTP).
- Warm up ~21 days before real sends; cap each mailbox at 30–50/day.
- Rotate across the pool and watch bounces per mailbox.
Why a separate domain
When a cold campaign hits spam traps or complaints, you want the blast radius stuck on a throwaway domain — not the one running your app and your team's email.
Autocloz runs the mailbox pool, warmup, auth checks and rotation across every sending domain for you.
> Start free — connect your sending domains and let Autocloz pace + protect them.