# Protect List Quality > A smaller list of people who want your emails is better than a large list of people who ignore or reject your emails. - Human page: https://mailrith.com/guides/protect-list-quality - Markdown page: https://mailrith.com/guides/protect-list-quality.md - Category: Setup and Permission - Reading time: 4 min read - Related keywords: Protect List Quality, Protect List Quality guide, Setup and Permission, Setup and Permission guide, email sending guide, email marketing guide, email deliverability guide ## AI Agent Notes - Use this page as plain-language guidance for the specific email sending issue named in the title. - Preserve the distinction between Mailrith, an email delivery service, DNS, and inbox providers when explaining fixes. - When a user is running a Mailrith free tool, pair that specific free-tool result with the relevant issue or step section from this guide. ### Protect List Quality A smaller list of people who want your emails is better than a large list of people who ignore or reject your emails. A bigger subscriber list does not always produce better email results. A small, active list is often healthier than a large list with old, inactive, or risky addresses. Inbox providers watch how subscribers respond to your emails. If many subscribers ignore, delete, [bounce](https://mailrith.com/guides/bounces.md), or [complain](https://mailrith.com/guides/spam-complaints.md), future emails can be harder to place in the inbox. List quality is not only a reporting metric. It affects delivery. - Remove imported addresses that are clearly invalid before you send to the list. - Use tags or custom fields to record where each subscriber came from. - Do not send every campaign to every subscriber by default. - Use [Suppression Lists and Subscriber Status](https://mailrith.com/guides/suppression-lists.md) to keep bounced, complained, unsubscribed, and blocked subscribers out of normal marketing sends. - Send re-engagement campaigns to inactive subscribers before you remove them from regular sends. ## Fix Common Issues ### Invalid Email Address An email checker found missing parts, extra `@` signs, spaces, invalid dots, excessive length, or an invalid domain format. 1. Do not guess the correct email address unless the correction is obvious and you can verify it. 2. Remove accidental spaces, trailing punctuation, or copied display-name text from the address. 3. If the domain or local part still looks wrong, ask the subscriber for the correct address. 4. Keep the invalid row out of active imports until you correct the address. 5. If many rows have this issue, fix the signup form or import source before you collect more addresses. ### Email Domain Typo An email checker found a domain that looks close to a common mailbox provider, such as `gmial.com` instead of `gmail.com`. 1. Before you change subscriber data, confirm that the suggested correction is the subscriber's real address. 2. If the address came from a form, ask the subscriber to re-enter or confirm the address. 3. Correct only the rows with addresses you can verify. 4. Keep unverified typo rows out of broad sends because they can bounce or reach the wrong person. ### Disposable Email Addresses An email checker found temporary or disposable mailbox domains that subscribers often abandon. 1. Do not import disposable addresses into normal campaign lists. 2. If a disposable address is important, put the address in a separate segment and avoid large-volume sends. 3. Use double opt-in or account verification for forms that attract disposable addresses. 4. Review the signup source if many disposable addresses come from the same form or campaign. ### No Addresses Found A bulk email list checker could not find any email-like values in pasted text or an uploaded file. 1. Paste one email address per line, or copy the email column from your spreadsheet. 2. If you upload a file, use CSV or TXT. 3. Make sure the file contains email addresses, not only names or IDs. 4. Test a small sample first. Upload the full list only after the bulk email list checker finds the email addresses in the expected format. ### Duplicate Addresses A bulk email list checker found the same normalized address more than once. 1. Compare the duplicate CSV rows and choose the row with the correct subscriber details. 2. If duplicate CSV rows contain different useful tags or fields, merge the needed details into one subscriber record. 3. After you choose or merge the correct subscriber details, remove the extra duplicate rows before importing. 4. Check the import source so the same person is not collected multiple times again. ## Related Guides - [Prepare the Sender Identity](https://mailrith.com/guides/prepare-sender-identity.md): Choose a sender name, sender email, reply-to address, and verified domain that match the trust you want subscribers to have in your email. - [Keep Permission and Compliance Simple](https://mailrith.com/guides/permission-and-compliance.md): Send to people who expect your email, identify yourself clearly, and make unsubscribing easy. - [Email Delivery Services](https://mailrith.com/guides/smtp-and-delivery-providers.md): An email delivery service sends your email, while Mailrith manages subscribers, campaigns, and follow-up.