Cold email, in detail.
Fewer articles, written from what we actually run. For step-by-step guides and checklists, see the resources.
Stealth Redirect: Show a Website on Every Cold Email Domain Without Linking Them Together
A redirect publishes the link between every domain in your fleet. Stealth Redirect shows your website on each domain with no redirect behind it.
4 min read
InfrastructureHow to Buy Domains in Bulk for Cold Email Without Getting Flagged
393 domains across Spaceship, Dynadot and Cosmotown, in 36 purchase runs over 11 days. The buying pattern matters more than the extension once you are at scale.
5 min read
DeliverabilityWhy Instantly's Warm-Up Hurts Azure Deliverability
Azure mailboxes warmed on Instantly consistently return the weakest reply rates we see. Here is why, and what to use instead.
4 min read
DeliverabilityWhy We Do Not Recommend .info Domains for Cold Email
SURBL is blacklisting newly registered .info domains, often before you send anything. Here is why, and what it breaks.
3 min read
Mailbox TypesBest Cold Email Mailboxes for Agencies in 2026
Azure at €0.30 with the domain included, Google at €3.00 falling to €2.50. Which to run for which client, and what actually separates providers.
6 min read
InfrastructureWhat Cold Email Infrastructure Actually Costs in 2026
The per-inbox price tells you almost nothing. Here is the arithmetic that matters, worked through at 500, 1,000 and 6,000 sends a day.
7 min read
ScalingHow Many Mailboxes Do You Need for Cold Email?
Divide target sends by the safe per-inbox limit. Azure is 2 to 3 a day, Google up to 15. Everything else follows from that.
5 min read