The blacklist

The blacklist is a protected list of email addresses that cannot receive campaigns from your account. It is both a safeguard for your deliverability and a GDPR requirement. Keeping the blacklist intact is not optional, it is your documented record of opt-out requests and technically invalid addresses.

Why contacts end up on the blacklist

• They clicked the unsubscribe link in one of your emails.
• They submitted a spam complaint.
• Their email address returned a 5.1.1 hard bounce (address does not exist).
• Their address reached the configured maximum number of consecutive hard bounces.
• You added them manually.
• They were imported directly into the blacklist.

What the blacklist does

Blacklisted addresses cannot be re-imported into your active contact database.

Why you must not empty the blacklist

GDPR obligations

The GDPR gives everyone the right to object to direct marketing. When someone unsubscribes, that is a clear exercise of that right. Emailing them again is a violation of their privacy rights and exposes you to regulatory action. Fines under the GDPR can reach 20 million euros or 4% of annual global turnover.

Deliverability consequences

Email providers like Gmail and Outlook monitor complaint signals closely. If contacts who previously unsubscribed start receiving your emails again, they will mark them as spam. This damages your sender reputation and causes your emails to be filtered, not just for those contacts, but for your entire sending domain.

Legal consequences

Knowingly sending emails to people who have unsubscribed is not a grey area. It is a violation of European privacy law. In addition to regulatory fines, data subjects can pursue civil claims against you.

Frequently asked questions

"The person unsubscribed by accident. Can we put them back?"

Not manually. The only correct process is for the contact to resubscribe themselves through your opt-in form. When they complete the double opt-in, they are automatically moved back to the confirmed status. See "Resubscribing a blocked contact" for the full process.

"We have permission from a contact. Can we re-add them?"

Verbal or implied permission is not enough. You need documented consent, which is what a completed opt-in flow provides. Ask the contact to subscribe through your opt-in form. That creates a documented consent record.

"Can I remove an address that was blacklisted by mistake?"

If an address ended up on the blacklist due to a technical error, for example a hard bounce caused by a server configuration issue rather than an invalid address, contact support@flexmail.be. They can assess the situation and advise on the appropriate action.

Flexmail distinguishes between two types of blacklisted contacts, and what you can do depends on which type applies:

Manually blacklisted contacts

If a contact was added to the blacklist manually, because you did this yourself via the contact detail page, or because you imported them directly into the blacklist, you can remove them from the blacklist yourself. Go to Contacts > All contacts > Blacklisted, find the contact, and use the option to remove from blacklist. Only do this if you have a legitimate, documented reason and new consent from the contact.

Contacts blacklisted due to hard bounce or spam complaint

Contacts that ended up on the blacklist because of a hard bounce (5.1.1 error) or a spam complaint cannot be removed by account users. Flexmail locked this intentionally, for deliverability and compliance reasons. If such a contact has explicitly contacted you and provided fresh consent to receive your emails, contact support@flexmail.be with the request and the context. The support team assesses the situation and can, where appropriate, remove the address so the contact can complete a new opt-in process.

"Can I import old unsubscribers from another system?"

Yes, and you should. Before importing active contacts from another platform, import your previous unsubscribers directly into the Flexmail blacklist. This protects you from accidentally emailing people who have already unsubscribed. See "Add contacts" for how to import directly into the blacklist.

"We bought this list before GDPR. Can we email them?"

No. The GDPR applies to all data you currently hold, regardless of when it was acquired. Purchased lists almost never meet consent requirements. The contacts gave their data to a different organisation for different purposes. Emailing them exposes you to a violation.

"What about the right to be forgotten?"

Under the GDPR, contacts have the right to request that you delete their data. When you receive such a request, you must delete the contact from your database. However, you may need to retain the email address on the blacklist as proof that you processed their opt-out. The address alone, without other personal data, is the minimum needed to prevent accidentally re-adding them. Consult your data protection officer or legal counsel for guidance specific to your situation.

What should you do instead?

If you are struggling with a shrinking sendable list or low engagement, the right approach is to start re-engagement campaigns to win back inactive contacts before they unsubscribe, use segmentation to send more relevant content so people do not feel a reason to unsubscribe, improve your opt-in process to attract contacts who genuinely want to hear from you, and accept that a smaller, engaged list performs better than a large, unengaged list.

View your blacklisted contacts

1. Go to Contacts, then All contacts.
2. Click the Blacklisted tab.

The blacklisted tab shows each address, the reason why it was blacklisted, and the date. You can search by email address and sort by date.

Export the blacklist

Select contacts on the Blacklisted tab and use the Export option to download them as a CSV file. You can do this periodically to keep a local backup, or to import your unsubscribers into another system.

Add a contact to the blacklist manually

If you receive an unsubscribe request outside of email, by phone, in person, or via a contact form, you are required under the GDPR to honour it. To blacklist an address manually:

1. Go to Contacts, then All contacts.
2. Search for the contact.
3. Open the detail page and click Unsubscribe this contact.

If the contact is not yet in your database, you can import the address directly into the blacklist through the import flow.

Common mistakes to avoid

Removing contacts from the blacklist to re-import them

Manually removing someone from the blacklist and then re-importing them is not a valid resubscription process. It bypasses consent documentation and exposes you to GDPR risk. The correct procedure for re-adding a blacklisted contact is described in "Resubscribing a blocked contact".

Deleting blacklisted contacts to clean up the list

Deleting contacts on the blacklist removes your record that those people unsubscribed. If they appear in an import later, they are added as active contacts with no unsubscribe history. The blacklist is not clutter, it is protection.

Not importing unsubscribers before migrating

When migrating to Flexmail from another platform, many users import their active contacts first and plan to add the blacklist later. If you send a campaign before finishing the migration, you email people who previously unsubscribed. Always do the blacklist import first.

Next steps

• See "Resubscribing a blocked contact" for the correct process when a blacklisted contact wants to resubscribe
• See "About bounces" for how hard and soft bounces lead to blacklisting and how to configure bounce thresholds
• See "Add contacts" for importing previous unsubscribers from another platform directly into your blacklist