Notes from the deliverability lab.
How Danish Lead Co. ships mailbox cohorts in roughly the time it takes to grab a coffee
Founding-customer breakdown: domains bought, DNS auto-applied, Workspace mailboxes provisioned, warm-up tracked, exported to Smartlead - all without the team touching DNS.
The InboxLee TeamApr 26Why 2-to-3 mailboxes per domain is the deliverability ceiling nobody tells you
Why InboxLee refuses to provision a fourth mailbox on a single domain, what the domain-level signal actually is, and how to plan a ramp around it.
The InboxLee TeamApr 22Connect Smartlead to your InboxLee mailboxes in under a minute
API key method, CSV fallback, sending limits. Complete guide with every step spelled out.
The InboxLee TeamApr 22DKIM explained: what it is and why every cold sender needs it
What DKIM does, why 2048-bit, how propagation works, what InboxLee sets automatically.
The InboxLee TeamApr 20SPF records for cold email senders: the complete no-fluff guide
What SPF does, why you need exactly one record, the common errors, and what InboxLee configures.
The InboxLee TeamApr 15Pre-Warmed mailbox marketplace goes live
Pre-warmed mailboxes on aged domains. Full provenance logs per mailbox. Day-one sending.
The InboxLee TeamApr 10SPF, DKIM, and DMARC: the cold-email checklist Google actually checks in 2026
The three records every cold sender needs, what each one does, what Google and Microsoft penalise when they are wrong.
The InboxLee TeamApr 8DMARC p=quarantine vs p=reject: which one is right for cold email
Reject sounds stronger. Quarantine ships safer. Here is the operator-grade reasoning for picking the right policy.
The InboxLee TeamApr 7DKIM key rotation for cold email: when, why, and how often
Rotation is operational hygiene, not a security stunt. Here is the cadence that holds up under enterprise audits and Gmail postmaster scrutiny.
The InboxLee TeamApr 5DKIM 1024-bit vs 2048-bit: which one to publish in 2026
1024-bit keys still work. They are also a 1990s-era cryptographic compromise that modern enterprise mail servers are starting to flag.
The InboxLee TeamApr 4