Notes from the deliverability lab.
Google Workspace vs Microsoft 365 for cold outbound: where each one wins
Workspace and M365 both work for cold email. They differ on cost, throttling behaviour, and partner economics.
The InboxLee TeamMar 4Dedicated SMTP for cold email: when it is worth the upgrade
Dedicated SMTP is overkill for most senders and essential for some. Here is the volume threshold where the math changes.
The InboxLee TeamMar 1JMRP and FBL explained: how to read complaint loops as a cold sender
JMRP and FBL are the only direct complaint signals Microsoft and Yahoo provide. Most cold senders never see them.
The InboxLee TeamFeb 26Reverse DNS (PTR) for cold email senders: what it is and when to fix it
PTR records are usually somebody else's problem. Here is when they become yours.
The InboxLee TeamFeb 22TLS 1.2 (and 1.3) for cold email: why opportunistic encryption matters
Mail in transit should be encrypted. Most providers enforce TLS 1.2 or higher. Here is the operational impact.
The InboxLee TeamFeb 19Mailbox warmup mechanics: what actually happens during the 14 days
Warmup is not magic. Here is what providers see and how they decide your reputation is real.
The InboxLee TeamFeb 15Managed DNS vs registrar DNS: which one to use for cold-email domains
A dedicated managed DNS provider is faster, more reliable, and more reportable than most registrar DNS. Here is the trade-off.
The InboxLee TeamFeb 12Managing 30+ cold-email domains without losing your mind
A portfolio of cold-email domains is an operational system. Here is how to track, renew, and rotate at scale.
The InboxLee TeamFeb 8Connect Instantly to your InboxLee mailboxes in 60 seconds
API-key sync, sending limits, daily caps. Step-by-step with screenshots-grade detail.
The InboxLee TeamFeb 5Connect Lemlist to your InboxLee mailboxes
API-key method and CSV fallback for Lemlist users. Includes daily-cap configuration and warmup notes.
The InboxLee TeamFeb 2