Lindy suits a team that already works in Slack. Kaer suits a business that answers mail for several clients. Both draft replies, but they differ in how the mailbox connects and who pays for each person who touches it.
Does the inbox have to move?
Not with Kaer. The guide to answering enquiries says you can connect an existing mailbox over IMAP with an app password from your provider, and a connected mailbox stays where it is. The other route is a new Kaer address, which the Mail page describes as a Kaer mailbox on your domain.
Kaer's page on managing client inboxes names the cases to check. Gmail has a direct connection, which is in beta. Microsoft 365 mailboxes often do not allow IMAP app passwords, so the page says to test yours or forward that mail to a Kaer mailbox. Test each mailbox before you promise it to anyone.
Lindy's homepage lists Gmail among the tools it works across, and says it drafts, schedules and replies without leaving your email. Its pricing page says it connects 2 to 5 inboxes, depending on the plan.
Who sends the reply, and when?
Lindy's pricing page answers this directly. Anything with outside impact, such as sending an email, waits for approval. Read-only lookups from approved sources do not.
Kaer drafts by default and a person approves. The enquiries guide puts the choice under Settings, Mail, Triage and AI: Manual, Semi-auto or Full auto. In Semi-auto every reply waits for Approve and send. In Full auto, replies stop at the hourly cap you set. You can also turn on auto-reply for one kind of message, and set an escalation address for anything Kaer should not handle.
| Question | Lindy | Kaer |
|---|---|---|
| Where you work with it | Slack threads and mentions, email and iMessage | The Mail inbox, where drafts wait for you |
| How the mailbox connects | Gmail among its integrations, with 2 to 5 inboxes depending on plan | A Kaer mailbox on your domain, Gmail in beta, or IMAP with an app password |
| Who is billed | Every active user in the workspace | Paid plans, with up to 3 invited people per workspace |
If you choose Kaer, this order works: approve or edit every draft at first. Kaer's client inboxes page gives the same order, then switching on auto-replies for one type of message once it is always right, and leaving everything else waiting.
Where is Lindy the stronger choice?
When the inbox is one part of a team that already lives in Slack. Lindy's homepage says an admin installs it in Slack, everyone else links with one tap, and anyone can @mention it in a channel it has been added to. Its pricing page lists a Slack-native teammate that works in threads and mentions. Kaer's pricing page lists Slack among its connectors from the Cirrus plan up.
Both can work a tool that has no integration. Lindy's homepage says that if a tool has neither an integration nor an MCP server, Lindy can drive the browser like a person would, on Pro and up. Kaer's pricing page lists working portals with no integration on its paid plans. On that point the two are close.
Where is Kaer the stronger choice?
When one business answers mail for several clients. Kaer's client inboxes page says every paid plan includes unlimited workspaces. Each client can have its own workspace, mailbox and written brief, with up to 3 invited people in each, and only the people on that account invited.
Drafts then come from that client's facts. The same page says Kaer uses the prices, policies, opening hours and past answers you gave it for that client, in the tone you describe. Tell it which subjects and senders to leave alone, such as complaints and legal letters, and it keeps them out of its drafts for a person to answer.
What does each one cost?
This article does not print prices. Read both pricing pages on the day you decide. Kaer's pricing page sets out each plan line by line. Starter is free and needs no card, but its agent inbox row is marked not included, and Breeze is the first plan that lists one.
Lindy's pricing page bills every active user in the workspace, and all seats draw on one shared pool of credits. Its FAQ says anyone who uses Lindy takes a seat, including someone who only @mentions it in Slack. Lindy charges for every active user and Kaer charges by plan, so the two figures are not like for like. Count everyone who will touch the inbox before you compare them.
How do you set up Kaer for enquiries?
The enquiries guide has five steps:
- Open Mail and choose New Kaer address, or Connect a mailbox I have, then enter its address and app password. Test the connection, then connect the mailbox.
- Let it sort a morning. Today shows a brief of what needs you and the drafts waiting. Check it sorted things the way you would.
- Open a thread, click Reply, then Draft with Kaer. Edit if needed, then Approve and send, Discard or Regenerate.
- Choose Manual, Semi-auto or Full auto under Settings, Mail, Triage and AI, and add an escalation address.
- To use your own domain, add it under Settings, Mail, Domains, publish the TXT record it shows with your domain provider, and click Verify now.
Lindy's homepage and pricing page, and Kaer's enquiries guide, Mail page, client inboxes page and pricing page, as they read on 9 November 2026.
Frequently asked questions
Can I see how Kaer reached a draft?
Yes. Kaer's client inboxes page says each task keeps the steps it took and the tools it used, and its pricing page lists activity history on every task, including the free Starter plan.
Does Kaer send from Gmail without asking?
Not by default. Its client inboxes page says sending from Gmail needs Enable Gmail sending switched on, and then each message is held with a preview until someone approves or edits it.
What does Lindy do when credits run out?
Its pricing page says it pauses credit-using actions until credits reset at the start of the next cycle, and admins can top up before then.