Cold email, in detail.
Fewer articles, written from what we actually run. For step-by-step guides and checklists, see the resources.
The 7 Best Azure Mailbox Providers for Cold Email in 2026
Seven Azure mailbox providers compared on price, included domain, setup, sending guidance and support. Frostmailer from €30 per tenant with the .com domain included.
8 min read
Email MarketingFrostmailer vs Maildoso: Real Microsoft Inboxes or SMTP Mailboxes?
Compare Microsoft-hosted Outlook inboxes vs SMTP mailboxes: costs, domain control, and warm-up. Example: €30/month per tenant and 14-day warm-up.
8 min read
Email MarketingFrostmailer vs Primeforge for Microsoft 365 Cold Email Inboxes
Compare Frostmailer and Primeforge for Microsoft 365 cold email: Frostmailer from €30/tenant; Primeforge starts at $4.50/slot.
8 min read
Email MarketingFrostmailer vs ScaledMail for Outlook Inboxes: Price per Tenant Compared
Compare Frostmailer (€30/month per tenant) and ScaledMail ($50/domain) for 25 to 100 Outlook inboxes, including sending limits, warm-up, and add-on costs.
7 min read
ComparisonsBest AI GTM and Lead Generation Agencies in 2026: 12 Compared
OneGTM, Shields Outbound, The Kiln, Growth Engine X, RevPartners, Belkins and more, split into GTM engineering and done-for-you lead generation agencies.
9 min read
Email MarketingManaged vs. DIY Cold Email Setup: Costs and Control
Compare managed, DIY, and hybrid cold email setups: costs, control, ownership; includes Frostmailer pricing from €30 per tenant.
10 min read
Email MarketingCold Email Mailbox Rotation: How It Works and When
Send 4,000 cold emails a day across 20 Azure domains: set per-inbox caps, rest domains without pushing the rest harder, and rotate the infrastructure every six weeks.
6 min read
InfrastructureBest Cold Email Infrastructure for Agencies in 2026: 10 Providers Compared
Frostmailer, InboxKit, Primeforge, Hypertide, ScaledMail, Zapmail and more, compared on Microsoft and Google pricing, domains and done-for-you setup.
8 min read
ComparisonsInboxKit Alternatives in 2026: 7 Options Compared
Where Frostmailer, Primeforge, Hypertide, ScaledMail, Zapmail, MailDeck and Premium Inboxes fit better than InboxKit, with prices from each provider's own site.
6 min read
DeliverabilityStealth 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 €30 a tenant with the .com 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