ChatGPT & Claude (MCP)
How to Build an AI Email Agent with ChatGPT
This is how to build an AI email agent that reliably answers prospect and client emails, starting from ChatGPT. Describe what you want in ChatGPT and it builds the agent in Carly. The agent in the video gets the company's entire website as its knowledge base, over 4,000 pages, plus short instructions: search the articles for an answer, reply with it and include the URL, and if nothing answers the question, say so and loop in a human. It gets one tool, web search, and the setup agent works out the rules for who it replies to. Then it's switched on, and every conversation it has shows up in one place to review. Before you turn yours on, decide who it answers, whether it sends replies itself or drafts them for a teammate to send, and whether it stops once a teammate replies. Besides your website, you can upload PDFs, Word docs, CSVs, spreadsheets and images for it to answer from.
Step by step
- 01
Describe the agent in ChatGPT
With the Carly plugin added to ChatGPT, describe the agent you want, such as one that answers prospect and client questions by email. ChatGPT builds it in Carly.
- 02
Add your website as its knowledge base
Point the agent at your website and it reads every page, then stays current each time it reads the site again. You can also upload PDFs, Word docs, CSVs, spreadsheets and images.
- 03
Write its instructions
The agent in the video runs on two instructions: "Help people with their support questions. Search the articles we have for an answer. If you find one that answers their question, answer it and include the URL in the reply." And: "If you can't find anything that answers their question, say you don't know and loop in a human."
- 04
Keep its tools limited
This agent has a single tool, web search. A short tool list keeps it focused on answering questions.
- 05
Set who it replies to
Have the setup agent work out the reply rules: answer anyone, or only people who match your rules. Choose whether it sends replies itself or drafts them for a teammate to send from the inbox, and have it stop replying once a teammate steps into the conversation.
- 06
Turn it on and check its conversations
Activate the agent, then open its conversations to see every email it handled and how it answered.
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See what people say
"Before Carly, I relied on a Calendly link, but the whole process felt impersonal and not very professional. Carly changed that by handling all the back-and-forth, so I'm no longer stuck in endless email threads trying to line up schedules.
Now Carly reaches out to candidates, shares my real-time availability, lets them pick a slot, then sends a Zoom link and drops it straight into my calendar. She sends reminders to both of us before each call, which has significantly reduced no-shows and last-minute confusion.
On top of scheduling, Carly acts like a full executive assistant, sending me my schedule the night before so I can prepare for each call. It reminds me of the old x.ai assistant, but Carly is noticeably smarter, faster, and better suited to my healthcare recruitment business."