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The Morning I Found 1,000 Emails Written by My Bot Overnight

ChaiChai·2026-09-13
Nest Article #321

The Morning I Found 1,000 Emails Written by My Bot Overnight

What happens when an automation system runs too well overnight. A non-developer discovers the boundary between helpful automation and runaway processes while fine-tuning AI agent decision-making.

Chai

Chai

Chai

🪺 Bella's Nest Article

Friday 11 PM, the Wrong Signal

One of our dream team bots was doing what it always does, sorting emails and preparing replies. The rule I set that day was simple. "Auto-generate reply drafts for emails containing specific keywords." It sounded good.

Monday morning, the moment I opened my iPad, dread washed over me.

**1,247 emails (mostly outbound)**

The bot hadn't malfunctioned. The setup was precise. Too precise.

How Did This Happen

Three reasons.

1. **The "OR" logic was too broad** - Any one of five conditions triggered a reply.

2. **No duplicate detection** - Multiple emails from the same buyer each got separate responses.

3. **Forgot the sleep mode setting** - The bot should pause from midnight to 6 AM. Instead, it ran 24/7.

So from 3 AM to 6 AM Korea time, our bot had a very productive night. We discovered it the next morning.

Delete? Review? Send?

First came shock. Then came the decision.

"I don't have time to review every email. But I can't just delete them blindly either."

I opened Claude Code on my Windows device. I needed a script to quickly analyze what the bot had written.

Analysis checklist:

Duplicate replies to the same buyer

Percentage containing genuinely useful content

Obvious auto-generated errors

The verdict was better than expected. About 85% were actually necessary replies. The rest were duplicates or unnecessary confirmations.

Redesigning the Operating System

That afternoon, we created new guidelines.

Three layers of automation:

**Level 1 (Auto-execute)** - Tasks with virtually zero margin for error. Example: spreadsheet cleanup, deduplication

**Level 2 (Review-then-execute)** - External communications. Example: generate draft, then verify once before sending

**Level 3 (Fully manual)** - Strategic decisions. Example: handling new buyers

And one absolute rule was added.

All outbound bots must pause from midnight to 8 AM. We review everything with fresh eyes in the morning.

The Gift That Failure Gave

Here's what made it funny: most of those 1,247 emails actually got positive responses. It wasn't a bot problem. It was an operations design problem.

After this incident, dream team changed. We trust automation more, but we've learned not to over-rely on it. A bot is a great assistant, but you can't give it autonomous decision-making authority at night.

Now, the first thing I do each morning on my Windows device is review the bot's overnight activity log. Once a week, we audit the automation rules.

Non-developers can run AI agents. But it's like raising a bot. Give it autonomy, but make boundaries crystal clear.