The blacklist

The blacklist is a protected list of email addresses that cannot receive campaigns from your account. It is both a deliverability safeguard and a GDPR requirement. Keeping it 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 accumulated the configured maximum number of consecutive hard bounces.
• You added them manually.
• They were imported directly into the blacklist.

What the blacklist does

Flexmail automatically skips blacklisted addresses in every campaign send, even if a blacklisted address appears in a segment you have selected. Blacklisted addresses also cannot be re-imported into your active contact database.

Why you must not empty the blacklist

GDPR obligations

GDPR gives every person 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 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 EU 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 re-subscribe themselves through your opt-in form. When they complete the double opt-in, they are moved back to confirmed status automatically. 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 sufficient. 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 that was triggered 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.

"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 opted out. See "Add contacts" for how to import directly to the blacklist.

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

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

"What about the right to be forgotten?"

Under GDPR, contacts have the right to request that you delete their data. When you receive such a request, you should delete the contact from your database. However, you may need to retain the email address on the blacklist as a record 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 run re-engagement campaigns to win back inactive contacts before they unsubscribe, use segmentation to send more relevant content so people do not feel the need to unsubscribe, improve your opt-in process to attract contacts who genuinely want to hear from you, and accept that a smaller, engaged list outperforms a large, disengaged one.

View your blacklisted contacts

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

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

Export the blacklist

Select contacts in the Blacklisted tab and use the Export option to download them as a CSV. You may want to do this periodically to maintain 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 obligated under GDPR to honour it. To manually blacklist an address:

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

If the contact is not in your database yet, you can import the address directly into the blacklist from 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 re-subscription process. It bypasses consent documentation and exposes you to GDPR risk. The correct process for re-adding a blacklisted contact is described in 'Resubscribing a blocked contact'.

Deleting blacklisted contacts to clean up the list

Deleting blacklisted contacts removes your record that those people opted out. If they later appear in an import, they will be added as active contacts with no opt-out 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 will 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 re-subscribe.
• See "About bounces" for how hard and soft bounces lead to blacklisting and how to configure bounce thresholds.
• See "Add contacts" for how to import previous unsubscribers from another platform directly into your blacklist.

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