TL;DR
Your Bundle's inboxes appear on the Inboxes page automatically after setup. Use this guide only for inboxes you already own.
Open Inboxes and click Connect inboxes.
Choose CSV (Bulk Email Addition), Google (Gmail / GSuite), Outlook (Hotmail, Live, MSN) or Other (Any provider, IMAP).
Inboxes on new domains need 14 days of warmup before you send campaigns from them.
When you'd use this
Use this to send from a domain or mailbox you already have, alongside or instead of your Bundle inboxes. For Bundle inboxes, see What are pre-warmed inboxes, how do I set them up, and what if they're out of stock?
Step 1: Open Connect inboxes
Sign in at next.listkit.io.
Open the Inboxes page from the sidebar.
Click Connect inboxes. You see four options.
Option 1: CSV (Bulk Email Addition)
Best for adding many inboxes at once.
Click CSV Sample to download the format.
Fill it in using the exact structure of the sample.
Click Upload and choose your file.
Continue. A summary shows which inboxes were added, skipped (already in your account) or failed (errors in the file or credentials).
Option 2: Google (Gmail / GSuite)
The inbox then appears on the Inboxes page.
Option 3: Outlook (Hotmail, Live, MSN)
Use this for Outlook, Hotmail, Live and MSN addresses, and for Microsoft 365 business mailboxes.
Click Connect under Outlook.
Sign in and approve access.
Option 4: Other (Any provider, IMAP)
Click Connect under Other.
Enter your IMAP connection details from your email provider.
Complete the connection.
Expected outcome
Your connected inboxes are listed on the Inboxes page and can be selected in campaigns. Replies to them come into Master Inbox. Inboxes on new domains need 14 days of warmup first.
FAQ
Can I use a domain I already own?
Yes. Connect that domain's existing mailboxes here. ListKit can't create new inboxes on your domain or take a domain transfer.
It says the inbox is already added to your account.
Message us with the address. It's usually still linked somewhere else on our side, and we can clear it.
Do my own inboxes need warmup?
Inboxes on new domains need 14 days of warmup before you send campaigns from them. Every inbox also ramps up from 1 email a day. See How do warmup and ramp-up work, and when can I start sending?
Why was my inbox skipped?
It's already connected to your account.
Why did my inbox fail to import?
Check the CSV format against the sample and check the credentials.
Why can't I launch a campaign?
A campaign needs at least one connected inbox that is ready to send.
Can I mix connection methods?
Yes. You can connect some inboxes with Google and others with CSV or IMAP.










