What a migration copies
An email migration copies the messages in the old mailbox into the new mailbox. The domain itself can stay where it is. The website can stay where it is. The record that changes is the MX line, which is where mail goes. The new mailbox can fill up before MX changes. People and ordinary mail still go to the old server. This order is separate from a site move. A WordPress migration is files and a database. The mailbox is not a step in that article. The site steps are in the WordPress migration article.
The OwnHost corporate mail page lists the move as free. It names Yandex, Google Workspace, Office 365, and cPanel or Plesk as sources. The FAQ adds that the job depends on IMAP access at the source server. If IMAP is closed, the copy may not finish. A “without data loss” sentence is in the feature text. A closed mailbox not losing mail does not mean a copy is taken when there is no access. The local email page also lists free migration and setup. The same IMAP condition applies there.
1. Write down the mailboxes and the size
List every address, the approximate fullness, and the aliases. Do not treat a group address as a real mailbox. Corporate Mail 10 is 10 mailboxes and 100 GB of total space. The monthly price is $4.99. Twenty-five mailboxes are 250 GB and $8.99. Fifty are 500 GB and $16.99. One hundred are 1000 GB and $32.99. The space is shared. If the old archive is over 100 GB, it does not fit the 10-mailbox card. The same mailbox counts on the local page show $3.99, $7.99, $15.99, and $30.99. The order is the card on the page you chose.
The 1 GB mailboxes on WordPress hosting are not this pool. When you move them onto a corporate plan, add up the GB again. A small hosting mailbox does not mean the archive is small. The export size is the real measure.
2. Do not close the old service
The first job is not deleting the old mailbox. If IMAP is open, the copy is taken with a client or through a support request. Do not change the old password until the copy finishes. A changed password drops a copy that is halfway done. If two-factor login wants an app password, create one and put it inside the request. Do not post the password in a public channel.
New mail keeps arriving in the old mailbox during the copy. That is why a short second sync is needed after the copy and just before MX changes. One pass can miss the last hour.
3. Open the new mailbox and check it
Open the same addresses on the new account. Look at a few messages, folders, and attachments. The calendar and contacts may not be inside the mail copy. They need ActiveSync or a separate export. The local card has no ActiveSync line. If contacts must move, write that in the request. The detail is in the protocol article.
Read one message in webmail. See that the reply leaves the new server, before MX changes, by sending only to a test recipient. The hourly limit is about 500 messages. Keep the test under that limit. Do not push a newsletter list from the new mailbox. Bulk mail is forbidden on this service.
4. MX changes last
In DNS, point the MX record at the target written in the new account’s panel. Do not memorize the target from this article. The line in the panel is the one that counts. Lowering the TTL a day before the change shortens the wait. You do not have to delete the old MX in the same minute. Let the new MX be the preferred one. Leave the old service up for a few days. Mail that still lands on the old mailbox before propagation ends stays there. Take it with the second sync.
Do not touch the website’s A record. An MX change does not move the site. Changing the site’s A record together with the mail sends the site to a new address too. If that is not wanted, only MX changes.
5. When to close the old account
Close the old service after incoming and outgoing mail have flowed on the new mailbox for a few days. Take a last sync before you close it. An OwnHost backup covers the period after the account exists. The archive backup at the old company does not arrive by itself. Restore happens when a backup exists on the OwnHost side. A message from before migration day that was never copied is not in that backup either.
Plan choice and limits are in the plans article. Where the mailbox sits is in the local email article. Do not mix the three. Write the size first. Then pick the page. Then copy. MX comes last.
Frequently asked questions
Short answers to the questions this article is most often asked.
1 Is email migration free?
The corporate mail and local email pages list the move as free. The FAQ says it depends on IMAP access at the source.
2 When does MX change?
After the copy has been checked. The old service stays up for a few days. The site’s A record is left alone.
3 Does the newsletter list move too?
No. Bulk mail is forbidden on this service. The move is for correspondence already in the mailbox.