Cold email marked yes or no
u/rasmusnilselid uses Claude Code to mark companies yes or no and to look up the email host. Unknown catch-all addresses are left out. He writes that the bounce rate sits at something like 0,05 percent. MailSpot writes drafts he reads before sending.
Done with Claude CodeModerate
What was done
On 13 May 2026 u/rasmusnilselid writes in r/coldemail that he has done cold email for his business for three years. With Claude Code in recent months he starts from a broad company list in Apollo and exports it for free. A segmentation tool fetches the site and marks the company yes or no against the ICP. No is removed. Yes is imported back into Apollo, and the emails are downloaded there. He built a similar tool for MX lookup. In his example a list of 10,000 leads can be checked, and if the senders are Google, mail goes only to Google addresses. Before, he kept addresses that passed and unknown catch-alls. The bounce rate then sat from 1 percent to 10 percent. Now the unknown ones are out, and he writes that the bounce rate sits at something like 0,05 percent. He writes that this needs a large market, and that good leads marked Unknown are lost. MailSpot categorises and writes drafts for people who showed interest. On a typical day he has about 30 follow-ups. He reads them and sends them himself.
How it went
The lists are marked and filtered before emails are downloaded. He sends the follow-ups after reading the draft. The post does not give the reply rate on the Google filter.
Worth knowing
10,000 is his example for the list tool, not a stated volume for a named campaign. "Something like 0,05 percent" is his wording. The business is not named. MailSpot is a different tool from Claude Code.
How to do it
- Mark the companies yes or no against the description you actually sell to.
- Remove no, and remove unknown catch-alls before you download addresses.
- Read each draft. Do not send the email before you have said yes.
Try it with Claude Code
Mark the companies in [list] yes or no against [icp]. Remove no. Do not download addresses and do not send email until I say yes. A follow-up draft should cover [offer] and wait for me.
Replace text in brackets with your own.
Done when. You have a filtered list, and no email has been sent unless you have said yes.
Safety rule. The agent does not send email. You read the draft and say yes first.
Read the original
Read the original · u/rasmusnilselid on Reddit ·