Field notes.
Most of these started as something that broke in production. The warmup post exists because we spent weeks warming a domain that was never warming, and the unsubscribe post exists because we shipped a 405 to Gmail.
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AI & MCP · 8 min
How to run cold email from Claude with MCP
A working setup, from empty account to an ordered sending domain and an approved campaign, entirely through an AI assistant. Connection string, tool order, and where it waits.
Read →Deliverability · 7 min
Your warmup dashboard is probably lying to you
Two domains, same setup. One captured 17 replies from 134 sends. The other captured zero from 99 and reported nothing wrong. How to tell which one you have.
Read →Deliverability · 6 min
The 405 that quietly breaks one-click unsubscribe
Gmail and Yahoo POST to your List-Unsubscribe URL. If your route only accepts GET, every one-click opt-out fails silently. We shipped this bug, then fixed it.
Read →More
AI SDR costs compared: FirstSales, Explee, Gojiberry, Raechly
Four AI SDR tools, four pricing models. We priced the same 1,000 prospects on each and checked whose inbox sends the mail and what the agent does unasked.
Pre-warmed inboxes vs your own domain: what a fast start costs
Some outreach tools send from inboxes they warmed months ago, so you can start today. Here is what you give up for that speed, and when it is worth it.
The four caps that keep a sending domain alive
Per mailbox, per domain, per campaign, plus a hard ceiling overriding all three. Why a cold email platform should refuse the volume you ask it for.
Never send cold email from your primary domain
The advice is common, the reasoning usually vague. Here is the specific mechanism, plus the MX trap that nearly took down our company email.
Point your assistant at it and see.
Connect the MCP server, tell it what you sell and pick your sending domain. You will know inside an hour whether this is the setup you want.