How to Use Claude Duet for Email Marketing
Claude Duet is Anthropic's proactive agent, released as a research preview on October 21, 2026. It runs on Claude Opus 5.5 in its own cloud computer, keeps working after you close the app, sends you a brief each morning, and checks your connected apps every few hours.
Most AI email advice is about writing copy. That is the least interesting thing Duet does for email. Its advantage is that it comes back on its own: it looks at your email platform while you are in meetings and tells you about the reply, the bounce spike, or the sequence nobody entered this week.
This guide covers the workflows where that matters. It assumes you have connected an email platform. If not, start with connecting Claude Duet to Sequenzy.
Check-Ins, Not Live Alerts
Before planning workflows, understand how Duet notices things. Anthropic says Duet checks your connected accounts every few hours, because checking nonstop would use up your plan's limits much faster. It messages you only when something needs your attention.
So Duet is a reliable colleague who looks in several times a day, not an alarm. Split email work accordingly:
- Check-in work: replies, bounce and complaint trends, failed imports, empty sequences, campaigns scheduled for today, weekly results. All of this can wait a few hours.
- Live work: pausing a broken send, transactional email, anything that must happen within minutes. Keep it in your email platform's own alerts and automations.
Set What You Want to Hear About
Anthropic says you can tell Duet what you want to hear about and how often. Do this first, in the Duet thread:
For email, only bring me these, from the Sequenzy connector:
- Subscriber replies that are questions, bugs, or cancellation risks
- Any send whose bounce or complaint rate is double its 4-week average
- Campaigns scheduled to go out in the next 24 hours, with audience size
- Sequences that had zero new entries this week
Put email items in the morning brief, at most three, ranked by what needs
my decision. Don't tell me about anything else in Sequenzy.The "at most three" matters. A brief that lists every metric from every app turns into something you stop reading.
Duet's background checks count toward your Claude usage limits. A short list of things to look for costs less at each check than "review everything".
Workflow 1: Morning Email Brief
Duet already sends a brief built from your email and calendar. With the instruction above, the email platform joins it. A useful brief reads something like:
Email (2 items)
1. 4 replies to the onboarding sequence overnight. One is a billing
question from a team-plan customer; draft answer ready.
2. "October product update" goes to 3,412 subscribers at 10am. The segment
grew 40% since Monday after the webinar import. Worth a look?The second item is the kind of thing Duet is good at: connecting a change in one place (an import) to a risk somewhere else (a send).
Workflow 2: Reply Check-In
Replies to marketing email are where customers tell you things: a bug, a buying question, a reason they are about to cancel. They also get buried.
Sequenzy collects replies in its inbox, so Duet can look for them at each check-in:
At each check-in, look in the Sequenzy inbox for replies since the last
check. For each one:
1. Read it with the email it answered and the subscriber's plan and history.
2. Label it: question, bug, cancellation risk, positive, or other.
3. For questions, draft a short answer in our voice.
Bring me only questions, bugs, and cancellation risks. Never send a reply
without my approval.With the default Safer agent access preset, Duet can read replies but not answer them, so you paste or adjust its draft in the Sequenzy inbox. To let Duet send approved answers itself, add the conversations:write scope to the connection's key under Custom.
After a couple of weeks, ask Duet to summarize the labels. If cancellation-risk replies cluster after one email, that email needs work.
Workflow 3: Deliverability Trend
Bounces and spam complaints are small numbers until they suddenly are not. Duet cannot catch a spike within minutes, but it can catch a trend within hours:
At each check-in, compare bounce and complaint rates for sends in the last
48 hours with each send's 4-week average. Tell me only if a rate is more
than double, and include the counts, the mailbox providers involved, and
what changed in that send: new segment, new sender, new template.Workflow 4: Import Check
Imports go wrong quietly: a mapped column, missing consent flags, a list with every name in uppercase.
When you see a finished subscriber import in Sequenzy, check the new
subscribers: how many were added, how many lack a first name, any obvious
role addresses like info@ or admin@, and whether the consent field is set.
Tell me about problems before anything is scheduled to send to them.Workflow 5: Friday Review
For a weekly summary, ask once and let Duet track it in its Tasks tab:
Every Friday afternoon, review the week in Sequenzy, read only:
- Campaigns: sends, clicks, conversions, unsubscribes
- Sequences: new entries, completions, and any with zero entries
- One thing that improved, one that got worse, and one change to try
Keep it under 150 words.The word limit keeps the report readable on your phone, which is where you will see it.
Workflow 6: Brief to Draft
When you want Duet to make something, give it a brief with facts:
Draft a Sequenzy campaign announcing CSV export.
Facts: available today on all paid plans; docs at /docs/export.
Audience: paying customers active in the last 30 days, excluding anyone
who received a campaign in the last 3 days.
Goal: first export within 7 days.
Give me 3 subject lines and save the draft. Do not send or schedule.Open the draft in Sequenzy and read it there. Check the audience count as well as the copy; a wrong segment does more damage than an awkward sentence.
Workflow 7: Churn Signal to Test
Anthropic's own Duet demo shows it noticing churn after a pricing change and proposing a two-week test. The email version:
Find subscribers who finished our onboarding sequence 30 to 60 days ago,
never upgraded, and have not opened anything in 3 weeks. Tell me how many
there are and what they have in common, and propose a two-email win-back
test as an outline only.It stops at an outline. Once you like the plan, ask Duet to draft the emails and include new candidates in your Friday review.
Two Layers of Approval
Anthropic says Duet shows you exactly what it is about to do and waits for approval before it sends a message, makes a payment, signs a document, or deletes anything. If you cannot approve right away, it finishes the rest of the task and brings the approval back later.
That is the agent's layer. Add the platform's layer too: connect your email platform with a permission level that cannot deliver live email. In Sequenzy, the default Safer agent access preset reads data and drafts content but cannot send. Move to Marketing sender only after Duet's drafts have needed light edits for several weeks.
A sensible ladder:
| Stage | Duet does | Sequenzy preset |
|---|---|---|
| Week 1 | Briefs and reports only | Read-only |
| Weeks 2 to 4 | Drafts campaigns, tags contacts, prepares segments | Safer agent access |
| Later | Prepares sends you approve in Duet | Marketing sender |
What Duet Cannot Do Well Yet
- Real-time reactions: no documented event triggers; it checks every few hours.
- Plans and regions: the research preview is for Pro and Max subscribers in the US with a waitlist invitation. Team and Enterprise are not included yet.
- Watching it work: Anthropic says you cannot watch Duet's browser or take it over, so prefer connectors to browser use for email work.
- Some connectors: Anthropic says some connectors, such as Slack, work with limits in Duet, and Microsoft 365 is not available yet.
- Urgency calls: Anthropic notes Duet might misread a thread or misjudge what is urgent. Check its labels for the first few weeks.
FAQ
What can Duet do for email marketing?
Report, find replies, watch deliverability trends, draft campaigns, and check audiences, once an email platform is connected in Claude.
How is it different from a Claude chat?
It keeps working after you close the app, sends a morning brief, checks in every few hours, and tracks tasks.
Will it notice a reply immediately?
No. Replies wait until the next check, usually a few hours.
Can it reply to subscribers?
It can draft replies. Approve each send.
Next Steps
- Connect Claude Duet to Sequenzy.
- Compare the best email marketing tools for Claude Duet.
- For an agent that reacts to live email events, see how to use ChatGPT dots for email marketing.