Clean Your List Before Importing It Into a New CRM or Email Tool

When you move to a new CRM or email platform, you also move your problems unless you clean first. Old tools hide bad addresses behind years of history. A new account has no reputation at all, and the first sends matter a lot.

Why clean before the move

Many platforms measure your bounce and complaint rates from the start, and some pause accounts with a high bounce rate on early campaigns. Cleaning first protects your account, and it also reduces the number of contacts you pay for if the new tool charges by list size.

A migration checklist

1. Export everything from the old tool: the email address, the status (subscribed, unsubscribed, bounced), the sign-up date and any consent record.
2. Keep unsubscribes and bounces. Do not import people who unsubscribed or whose address bounced. Import your suppression list into the new tool, so it never sends to them.
3. Remove duplicates and fix obvious formatting problems such as spaces and capital letters.
4. Verify the rest on the bulk verification page and download the report.
5. Remove invalid addresses and import the valid group. Tag the accept-all and risky ones, so you can send to them later in small batches.
6. Warm up the new account: send a small first campaign to your most engaged contacts before widening.

Do not forget the consent record

Import the date and source of sign-up with each contact, if you have it. If you cannot show how a contact joined your list, think twice before sending. Rules differ between countries, so ask a qualified adviser if you are unsure.

Check the sending domain

A new tool usually means new sending settings. Publish the SPF, DKIM and DMARC records the platform asks for and check them with the SPF, DKIM and DMARC checker before the first campaign.

A one-off job suits credits

A migration happens once. Paying for verification only for this job, with credits that you buy once and use within 12 months, is simpler than a plan you do not need afterwards. Try a sample with the free credits of a new account first, then use the pricing page to pick a pack that fits the whole list.

After the move, keep the list clean: verify new sign-ups, and repeat the check before big campaigns. A tidy start is easy to keep tidy.

Mistakes during a migration

• Importing the suppression list last or not at all. Import people who unsubscribed or bounced first, so the new tool cannot send to them even by accident.
• Losing consent information. Export the date and source of sign-up together with the address.
• Switching the old tool off at once. Keep it for a while, in case you need to compare results or recover something.
• Sending the first campaign to the whole list. Start with your most engaged contacts and widen over a couple of weeks.

Questions people ask

Do I verify before or after cleaning duplicates? After. Duplicates inflate the number of credits you use, and they hide behind capital letters and spaces, so tidy first.

What about contacts without an email address? Import them as contacts without email, or leave them behind, depending on whether the new tool needs them for other work such as phone follow-up.

Can I verify addresses inside the new tool instead? Some tools offer a built-in check, and some charge extra. Doing it before the import means you pay only for the addresses you will actually load.

Import a sample first

Before the full import, load a small batch into the new tool and check field mapping, duplicates and consent flags. Fixing a mapping on fifty rows is easy; fixing it on fifty thousand is not.