Switching your team's email without losing a day of work

This is a checklist for teams moving their email to a new system without missing messages or losing a day of work. It covers listing what you have, moving data in stages, running both systems side by side, and changing the mail records last, with the steps for Nubo.

Changing the email system for a team is one of those jobs that looks small and then eats a week. The reason is rarely the technology. It is that email touches everything: customers write to a company address, invoicing tools send from it, people sign up for services with it, and calendars are full of invitations that point back to it. Move it carelessly and you find out about each of those dependencies one missed message at a time.

This guide is a checklist for doing the move calmly. It applies whether you are moving from one provider to another or from an older mail server that a previous IT person set up. The steps are the same; only the import tool changes.

List what you have

Before you touch anything, write down every address that receives mail. Most teams are surprised by the length of this list. It usually includes:

• One mailbox per person.
• Shared addresses such as info@, sales@, accounts@ and support@, and who reads them.
• Aliases, where several addresses deliver to the same mailbox.
• Groups or distribution lists that fan one address out to several people.
• Addresses that only exist to receive automated mail: payment alerts, domain registrar notices, monitoring.

Next, write down what depends on those addresses. Invoicing and accounting tools that send from a company address, forms on your website that email a notification, printers or scanners that send to email, and any service where the account owner’s login is an email address. When the old mailbox disappears, each of these is a surprise unless you have listed it.

Finally, note who needs what. A founder with fifteen years of mail is a different job from a new hire with two months. Decide up front how much history you will move and how far back.

Choose the switch time

Pick a quiet day. For most businesses that is a Friday evening or a weekend, so that a problem on the day has time to be fixed before the working week. Tell your team and your key customers a few days before, in plain language: on this date, we are changing our email system; nothing changes about your address; if you see a bounce or a delay, tell us.

The announcement matters more than it seems. It turns the first odd symptom, such as a message arriving an hour late, from a mystery into an expected side effect.

Keep the old system running through the whole process. You are not leaving a building and locking the door behind you; you are moving the front desk to a new room while the old one stays open for a while.

Move data in stages

Do not move everything at once. A staged move lets you check each layer before the next depends on it.

1. Contacts and calendars first. They are small and quick to move, and mistakes in them are easy to see. Check that recurring meetings survived, that time zones are right, and that shared calendars are shared with the right people.
2. Recent mail next. Move the last year, or the last quarter, depending on how people actually work. This is what everyone needs on day one.
3. Older archives last. Archives are large and rarely needed in a hurry. They can finish moving in the background after the switch.

After each stage, check a few mailboxes by hand. Pick a person who has an unusual setup, for example someone with many folders or a lot of attachments, and look at their mailbox on the new system. Folder structure, read and unread state, and attachments are the three things that most often go wrong.

If your team uses a mail program on their phone or laptop, plan the reconnection too. Each person will need to add the new account, and some will need help. A short written guide with screenshots, sent the day before, saves a lot of messages on the day.

Prepare the mail records

Email delivery is directed by DNS records on your domain, and a few of them matter for a move:

• MX records say where incoming mail for your domain goes. Changing these is the actual switch.
• SPF, DKIM and DMARC records tell other mail servers which systems are allowed to send as your domain. If you change systems without updating these, your messages can land in spam folders even though the move “worked”.
• The time-to-live (TTL) on each record says how long other servers remember the old answer. A long TTL means some senders keep delivering to the old system after you change the record.

The usual sequence is to lower the TTL on the MX records a day or two before the switch, so that when you change them the world catches up quickly. Add the new system’s SPF and DKIM records ahead of time, so that your outgoing mail is authenticated from the first message. Keep your DMARC policy gentle (monitoring only) until you have confirmed that everything legitimate passes.

In Nubo, the team owner adds the domain under Team in Home, and Nubo shows the DNS records to publish. Once the MX record points at mail.nubo.email, a check marks the domain as verified, and an owner or admin can then give each member an address on it. Nubo checks the MX record only. Other records, such as SPF and DKIM, stay your responsibility, so confirm what to publish for outgoing mail before you switch.

Change the mail records last

At the chosen time, change the MX records. Within minutes to hours, new mail starts arriving in the new mailboxes. During this window, a few messages will still go to the old system. That is normal, and it is why you keep the old mailboxes open.

Right after the change:

• Send test messages in both directions between the old and new systems and to an outside address you control.
• Check that replies to old threads land in the right place.
• Check that your outgoing mail passes authentication. Most mail services show you in the message headers whether SPF, DKIM and DMARC passed.
• Check forwarding rules, filters and out-of-office replies. Rules do not always move with the mailbox, and a missing filter can quietly send customer mail into a folder nobody reads.

Keep the old mailboxes read-only for a week or two. Someone will find a message that arrived there, or want an old attachment, and you will be glad to have it.

Tell the people who write to you

Most customers do not need to do anything, because the address does not change. Still, tell the people who have a reason to care:

• Your accountant and anyone who sends you regular invoices or statements.
• Services that send alerts to a particular address.
• Partners who may have your mailbox in a mail allow-list.

If any address does change, set up forwarding from the old one for as long as you can, and reply to people who write to the old address with a short note giving the new one.

Check and close the old system

Do not cancel the old plan on the day of the switch. Wait until:

• Everyone on the team has confirmed that their mail, calendar and contacts are complete.
• A week or two has passed with no messages arriving in the old mailboxes.
• Every automated sender on your list has been updated or confirmed.
• You have exported anything you need to keep for legal or accounting reasons.

Then cancel, and note the date in your records. If your old provider charges by the month, a few extra weeks of overlap is a small price for a quiet switch.

A migration done this way is boring, and that is the goal. If your team reads this and nothing noticeable happens on the day, the plan worked.