Email Migration: Moving Your Mail to Kapsule

How to copy existing mailboxes from another provider into KapsuleHost, mailbox by mailbox, without losing mail or taking your email offline.

Email migration is a self-serve wizard in KPanel. It connects to your current provider over IMAP, copies every folder and message into a Kapsule mailbox, and keeps running until you are ready to switch your incoming mail across. It is free on every plan. Your existing mail keeps working the entire time.

What You Need Before You Start

• The domain on your Kapsule account. See Adding and Connecting Your Domain.
• A list of the mailboxes you are moving, and the address each should land on here.
• Login credentials for each source mailbox. Most providers now require an app-specific password rather than the account password, and the wizard shows you the exact steps for yours.
• Room on your plan. The wizard compares the number of mailboxes you are adding against your plan's mailbox capacity and will tell you if you are over.

Step 1: Your Domain

Go to Migrations, choose the email option, and enter your email domain. The wizard looks up your current MX records and works out who you are moving from, so you usually do not have to tell it. It shows the detected provider and how confident it is.

Step 2: Connect to Your Current Host

Pick your provider from the list. Google Workspace, Microsoft 365, iCloud, Yahoo, Zoho and Fastmail are all recognised, along with a generic cPanel option and a plain IMAP option for anything else.

Choosing a known provider fills in the IMAP host, port and encryption for you, and tells you whether that provider needs an app password. If it does, the wizard gives you the steps and a direct link to the right settings page. For a generic IMAP source you supply the host yourself, normally port 993 with implicit TLS.

Step 3: List the Mailboxes

One row per mailbox. Each row has three fields:

• Source address, the address as it exists on your old host.
• Destination on Kapsule, where it should land here. It does not have to be the same local part, so you can tidy up naming as you move.
• Source password or app password, for that specific mailbox.

Then test each row. The test makes a real IMAP connection and reports back how many folders and how many messages it found. This is the most useful thing in the whole wizard: it proves the credentials work before you commit, and the message count tells you roughly how long the copy will take.

You cannot continue until every row tests successfully. A failed test names the reason, and the usual causes are an ordinary password used where an app password is required, IMAP switched off on the source account, or the wrong host.

Step 4: Cutover

Cutover means changing the MX records for your domain so new mail starts arriving at Kapsule instead of your old host. It is a separate decision from the copy, and it should be.

Choose I'll flip MX myself when ready. The wizard recommends it, and it is the path that puts the timing under your control. You do the copy first, check the mail actually arrived, and only then change MX.

Step 5: Review and Launch

Confirm the summary and launch. You land on a monitoring page and the sync starts immediately.

Watching It Run

The monitor refreshes itself every few seconds and shows:

• Mailboxes completed out of the total.
• Messages copied.
• Data transferred.
• When the run started.
• A progress row per mailbox, with the folders, messages and bytes done so far.

Things worth knowing about how the copy behaves:

• It never writes to your source. Nothing is deleted, moved or marked read on your old host.
• Read and flagged states are preserved, along with each message's original date, so your new mailbox looks like your old one rather than a wall of unread mail from today.
• It is resumable. It checkpoints as it goes, so an interruption picks up where it stopped instead of starting the folder again.
• A failing folder does not sink the mailbox. It is recorded and the rest continues.
• Large mailboxes take hours, not minutes. Tens of thousands of messages is a long copy no matter who does it.

Statuses you will see on a run are Discovering, Running, Awaiting cutover, Cutting over, Completed and Failed. Per mailbox you will also see Queued, Connecting, Discovering folders, Syncing, Delta syncing, Completed, Failed and Skipped.

Switching Your Mail Across

When the initial copy finishes, the run moves to Awaiting cutover and the monitor shows you the exact MX record to publish, with a copy button.

1. Publish that MX record for your domain. If your DNS is at Kapsule, do it on the domain's DNS tab. If your DNS is elsewhere, do it there. See MX Records.
2. Wait for it to take effect. New mail starts arriving at Kapsule as resolvers pick up the change.
3. Come back to the monitor and confirm you are done.
4. A final delta sync runs, picking up everything that landed in the old mailbox between the initial copy and the moment you switched. That is what stops you losing the messages that arrive during the changeover.

After the Migration

• Sign in to webmail and confirm the folder structure and message counts look right. See Webmail.
• Set up the mailbox on phones and desktops. Use IMAP, not POP3. See Email Client Setup, Mobile Setup and IMAP vs POP3.
• Check the Deliverability tab on the mailbox and publish SPF, DKIM and DMARC, or your outbound mail will land in spam folders. See SPF, DKIM and DMARC.
• Recreate forwarders, aliases and any shared addresses. They are configuration, not mail, so they do not copy across. See Email Aliases, Email Forwarding, Distribution Groups and Shared Inboxes.
• Keep the old account open for a few weeks. It costs little and it is the cheapest insurance there is.

If Something Goes Wrong

• A connection test fails. Almost always the password type or IMAP being disabled at the source. Regenerate the app password and retest.
• A mailbox shows Failed. Open the run and read the recorded reason, then start a new run for just that mailbox.
• Mail stops arriving after cutover. Check the MX record actually published and that nothing else is still claiming the domain. See Email Not Receiving and MX Records.
• Everything works but goes to spam. That is authentication, not migration. See SPF, DKIM and DMARC.

Quote your migration tracking ID when you open a ticket and support can look at the same run you are looking at. See Opening a Support Ticket.

Related Guides

• Migrations
• Importing Mail
• Email
• Setting Up Your Mailbox
• Hosting Glossary