How to Clean Your Email List Before Your Next Campaign

1. Export the contacts you plan to email

In your email service, select the subscribed contacts you want to send the newsletter to and export them as a CSV. Leave out people who unsubscribed or reported your emails as spam, along with addresses the service has already blocked after failed deliveries.

Save the original file. Keep names, tags, subscription status, and order details in it. You will use the email address to match the checker’s results back to these contacts later.

The file you upload needs an email column. You can upload several files together, and the checker removes repeated addresses across them. If the same subscriber appears in three exports, their address only needs one check.

Keep unsubscribe records when updating contacts, as Google’s subscription guidelines recommend.

2. Upload the CSV for a free check

Open the Email Quality Checker and choose Bulk check. Upload your file and check the number of addresses found. Each submission can contain up to 50,000 unique emails.

A smaller count than your spreadsheet is often explained by duplicates or blank cells. For example, a file with 3,000 rows might contain the same address more than once. The tool checks the unique addresses it finds.

Start the check and wait for the report. You will get a sending recommendation for each address, a chart of address types, and counts for shared inboxes and domains with strong spam filters.

3. Read the sending recommendations

The first numbers to look at are in the top-right corner. In this report, 92% of the addresses are marked Safe to send and 8% are marked Do not send. That is 2,486 addresses to keep for the campaign and 217 to exclude.

What the quality categories mean in your report

The chart groups your contacts by email type and quality. Use the table below to understand each group when reviewing your list.

Why 217 addresses are excluded

In this report, 143 addresses are Broken, 68 are Untrusted, and six are Disposable. Together, they make up the 217 addresses marked Do not send. Leave them out of the newsletter. If one belongs to an existing customer, you can ask for a corrected address separately without delaying the campaign.

How to read the shared-inbox and spam-filter counts

Below the chart, the report shows 1,076 shared inboxes and 61 addresses with strong spam filters. A shared inbox is used by a team, such as sales@ or support@. An address can appear in both counts: a team inbox can also have a strong spam filter. These are additional details about addresses already counted in the chart, not extra contacts.

The 61 addresses with strong spam filters may reject a campaign or send it to spam. Having a strong filter does not make an address invalid. Likewise, a shared inbox can belong to a team that wants your emails. Use the checker’s sending recommendation to decide which addresses to keep.

The single-address guide explains all four results if you want to examine a particular contact.

4. Download the results and update your mailing list

Choose Download report. The CSV contains an email address and four results on each row:

Filter the ok_to_send column: keep rows marked true for sending and exclude rows marked false. In this report, that gives you 2,486 addresses to keep and 217 to exclude.

Match these addresses to your original contact file. If a match fails, check for extra spaces or differences in capitalization before assuming the contact is missing.

Exclude the bad addresses in your email account

Use the group of 217 addresses to update your sending list. Depending on your email service, you can tag them for exclusion or remove them from the list used for this newsletter. Keep their purchase records and support history in the customer database.

The checker gives you the report; it does not change your email account. Check the recipient selection in that account before sending. Importing the report alone will not necessarily exclude anyone.

If you are importing the cleaned list into a new email service, use the 2,486 recommended addresses and bring over the names and other details from your original file. Keep the existing subscription status when matching or updating contacts.

Handle unfinished checks separately

If the result columns are blank, the check did not finish. Run those addresses through the checker again.

Unk in the quality column means the check returned an Unknown category. Use the ok_to_send recommendation for that address: include true and exclude false, just as you do for other completed results.

Your newsletter list now excludes the 217 problem addresses. The remaining 2,486 are ready for the campaign you selected them for.

Upload your list for a free quality check →

How much can list cleaning save?

The same bad address wastes another send every time you include it. In the report above, removing 217 addresses avoids 217 emails in one campaign, 868 across four campaigns, or 2,604 across a 12-email sequence.

If your plan charges by email volume, those sends remain available for other subscribers. If it charges by stored contacts, check the provider’s rules for archiving or removing contacts to reduce the bill.

There is also the cost of checking the list. Getsitecontrol gives you the chart, address categories, sending recommendations, and CSV download for free, with up to 50,000 unique addresses per submission.

For comparison, ZeroBounce’s published prices checked in October 2026 include a $39 minimum purchase for 2,000 verification credits and a $99 monthly bundle with 10,000 credits and additional tools. Paid services can include SMTP checks, which ask the receiving server about a specific inbox, as well as other email tools.

For the cleanup shown here, you get the information needed to remove the 217 problem addresses at no charge. If you also use a paid verification service, those excluded addresses no longer need to consume its credits.

Keep your list clean inside Getsitecontrol

If you send with Getsitecontrol Pro, contact quality is already available in your account. Each contact receives a Quality label, and the Dashboard shows the breakdown of your database.

You can use these labels when preparing the next newsletter, without exporting and checking the same contacts again.

Save a mailing list that excludes risky addresses

In Contacts, select Subscribed contacts. Use the Quality filter to exclude temporary addresses (Disposable) and untrusted addresses (Untrusted). Save the remaining subscribers as a segment. When you prepare a newsletter, choose this segment as the audience.

The segment updates as contacts match its rules. You can reuse it for future campaigns instead of building the same exclusion list each time. The contact management guide explains how to save and use segments.

Apply the exclusions to automated emails

Add Quality filters to automated promotional sequences as well. A temporary address collected by a discount popup should not receive a whole series of welcome emails after you have excluded it from newsletters. The Pro feature guide explains the available controls.

Block new disposable signups

Open the signup widget’s Anti-Spam settings and enable Filter disposable emails. Enable Filter untrusted emails to block that category too. These checks run after submission, before the address enters your contact database.

This prevents the same cleanup problem from building up again. Our disposable email guide walks through the signup filters, and the signup protection guide covers confirmation emails and bot protection.

When to check the list again

Check a new file before importing it, and check an older list before restarting a newsletter after a long break. A rise in failed deliveries is another reason to review the addresses you are using.

After the cleaned campaign, compare failed deliveries with the previous send. Keep an eye on spam complaints too. Google’s sender guidelines require the spam rate in Postmaster Tools to stay below 0.3%; that measures complaints, not failed deliveries.

Use the free checker for files collected outside your account. Inside Getsitecontrol, keep Quality filters and delivery safeguards in place so the next newsletter starts with a cleaner list.