Unsubscribes, suppression, and CAN-SPAM

SEMAOS treats CAN-SPAM compliance as a hard gate, not a suggestion: the product refuses to send email that would violate the two mechanical requirements. This article explains who you may email in the first place, what's enforced on every send, what happens when someone unsubscribes, and how to manage the suppression list.

Who am I allowed to email?

Only recipients who consented to receive commercial email from you, or who have an existing business relationship with you (a customer, an active prospect who gave you their address). That rule comes from three places at once: our Terms of Service, the laws that govern commercial email (CAN-SPAM in the US, CASL in Canada, GDPR in the EU/UK), and the sender guidelines of the inbox providers your mail has to get through — Gmail's sender guidelines make consent an explicit requirement, not a courtesy.

In practice:

• Purchased, rented, scraped, or harvested lists are not allowed on any plan or channel. Importing one violates the Terms and is grounds for suspension.
• The CSV import asks you to confirm consent before any rows are written. That attestation is per-file and required — the import won't start without it.
• Consent ages. A list that opted in three years ago and hasn't heard from you since will bounce and complain like a cold list. Re-permission old lists before mailing them.

The bounce and complaint thresholds described in Deliverability and bounces are how this rule enforces itself mechanically: lists without real consent generate complaints, and complaint rates above the threshold suspend sending automatically.

What does every email have to contain?

Two things, and SEMAOS enforces both at send time:

1. A working unsubscribe link. Templates place it with the {{system.unsubscribe_url}} merge field. The Simple editor writes the footer into every template it saves, so templates written there always carry one. The Designed editor lets you move or restyle the footer and shows a warning band if the merge field goes missing. A template without it cannot be sent at all. One-off sends are refused, and the composer's preview step tells you before you get that far: the email still renders so you can see the footer you need to fix, with the reason above it and the Next button switched off. A sequence will not activate, and the error names the step at fault. A broadcast is refused when you try to start it, before anything is queued. For an A/B test, every variant's template is checked, and the error names the variant at fault. If a broadcast holds part of its audience back to pick a winner, the template is checked again before the remaining recipients go out, in case it changed while the test was running.
2. Your physical mailing address, placed with {{system.mailing_address}}. This is the address you entered during onboarding. If a tenant somehow reaches the send path without one configured, the send is refused outright rather than delivered without the footer. A registered agent or virtual office address satisfies the requirement; it has to be a real postal address, not a working office.

These apply on both sending channels, mailbox and platform alike. Personal-feeling 1:1 mail is still commercial email under CAN-SPAM.

What happens when someone unsubscribes?

The moment a recipient clicks the unsubscribe link, their address joins your tenant's suppression list, and SEMAOS checks that list before every single send, on every channel. A suppressed contact is skipped by sequences, broadcasts, and one-off sends alike, and can no longer be enrolled in a new sequence. If they were already partway through one, every remaining step is skipped instead of sent — no further email reaches them. There is no grace window and no channel where the suppression doesn't apply.

Two other events add contacts to the same list automatically: a hard bounce (the address doesn't exist, so continuing to send only damages your reputation) and a spam complaint (the recipient told their provider your mail is unwanted, which is stronger than an unsubscribe).

Where do I see and manage the suppression list?

Under Settings → Suppression. You can select and remove entries (for example, someone who unsubscribed by mistake and asked to come back), and you can import a suppression list as a CSV, up to 10,000 addresses per file, which is the right first move when migrating from another tool: bring your old opt-outs with you before your first send, not after.

Removing someone from the list should be rare and always at their request. Re-mailing a genuine opt-out is the exact behavior CAN-SPAM penalizes, at up to five figures per email.

Why don't mailbox sends carry the List-Unsubscribe header?

Email has two unsubscribe mechanisms: the visible link in the body, and a hidden List-Unsubscribe header that inbox providers surface as their own unsubscribe button. SEMAOS adds the header on platform sends only. Mailbox sends deliberately omit it, because the header is a bulk-mail convention: Gmail and Outlook use its presence as a signal to file mail as promotional, and a 1:1 email from your own mailbox filed as bulk defeats the point of mailbox sending. The body link and the suppression check still apply in full on both channels, so the recipient's ability to opt out is never reduced; only the bulk-mail signaling differs.

Does any of this apply to the free plan?

All of it. The compliance gates are about the mail you send, not the tier you pay for. Free-plan mailbox sends carry the same footer requirements and run the same suppression check as a Business-tier broadcast.