Blacklisting a sender and deactivating an alias are two controls for stopping unwanted mail in AliasFleet. Blacklisting blocks one sender, domain, or pattern across every alias on the account, while each alias stays active for other senders. Deactivating an alias stops all mail to that one address, and mail sent while the alias is off bounces instead of queuing.
Neither option needs a plan change. The choice is about scope: one sender, or one alias.
How do blacklisting and deactivation differ?#
Blacklisting acts on the sender. When an incoming sender address matches a rule, the message is dropped before forwarding, and the sender receives a delivery failure. Senders not covered by the rule are unaffected, so the alias keeps working for everyone else. Because rules apply account-wide, a single rule covers every alias the sender might try.
Deactivation acts on the alias. Switching an alias off stops mail to that address from every sender. Mail sent during the off period bounces with a delivery failure and is not held for later delivery. The alias, its settings, and its history remain in the account, and forwarding resumes when the toggle is switched back on.
| Feature | Blacklist a sender | Deactivate an alias |
|---|---|---|
| What stops | Mail from one sender, domain, or pattern | All mail to one alias |
| Scope | Account-wide, across all aliases | One alias only |
| Other senders to the alias | Still delivered | Stopped |
| Mail while active | Dropped, sender gets a delivery failure | Bounces, sender gets a delivery failure |
| Reversal | Toggle the rule back on, or delete it | Flip the alias toggle back on |
| Alias history and settings | Untouched | Untouched |
Which option fits each situation?#
The deciding question is whether the sender or the alias causes the problem. A single problem sender points to blacklisting. A problem alias points to deactivation.
| Situation | Use blacklist | Use deactivate | Why |
|---|---|---|---|
| One sender spams an alias still needed for others | Yes | No | Alias keeps working for everyone else |
| A whole domain sends junk mail | Yes | No | One rule stops the whole domain |
| Rotating addresses from one domain send unwanted mail | Yes | No | Pattern matches the shared format only |
| The same sender spams several aliases | Yes | No | One rule covers all aliases |
| Alias shared widely; all its mail is unwanted | No | Yes | One step stops every sender |
| Alias needed again later, e.g. seasonal signup | No | Yes | Reversible; same address works again |
| Unclear whether the address is needed again | No | Yes | Alias and history are kept |
When does blacklisting work best?#
Blacklisting fits best when the alias still serves a purpose. Consider a shop alias used for order confirmations and delivery updates. If a third-party marketer that obtained the alias starts sending promotions to it, blacklisting the marketer stops the promotions while order mail from the shop continues to arrive. Deactivating the alias would stop both kinds of mail. The three block types are explained in full in Using sender rules.
When does deactivation work best?#
Deactivation fits best when the alias itself causes the problem. An alias created for a one-off event signup can start collecting marketing mail months later, from many different senders. No single sender rule solves that case, because each new sender needs its own rule. Switching the alias off stops all of it at once, and switching it back on restores the same address if the event returns. The same approach suits a pause between seasons for a seasonal signup, since mail sent while the alias is off bounces rather than queuing.
How do I blacklist a sender?#
- Open Sender Rules. Go to the Sender Rules page and select the Blocked Senders tab.
- Add a rule. Click Add Blocked Sender.
- Choose a block type. Select Exact Email for one address, Entire Domain for a whole domain, or Pattern for a wildcard format using
*and?. - Enter the address, domain, or pattern. For an Entire Domain rule, check Include subdomains to also block addresses on subdomains of that domain.
- Add a reason (optional). A short reason makes later reviews of the rules easier.
- Save the rule. Click Add Rule. The rule takes effect at once.
- Check the blocked count. Each rule shows how many messages it has stopped, which confirms whether the rule is catching mail.
How do I deactivate an alias?#
- Find the alias. Locate the alias in the alias list.
- Switch the toggle off. On the alias card, click the toggle; green means active, grey means off. The same toggle appears in list view and at the top of the alias detail page.
- Check the toggle state. There is no confirmation step, so the toggle showing the off state serves as the confirmation.
- Reactivate when needed. Flip the same toggle back on to resume forwarding. Only mail sent from that moment onward arrives; mail sent while the alias was off is gone.
Full detail on deactivation is in Activating and deactivating an alias.
Can both options be used together?#
Yes. The two controls are not mutually exclusive. A fully compromised alias can be deactivated, and the worst offending domains can also be blacklisted, so those senders cannot reach other aliases either. The reverse order also works: start with a blacklist rule for a single sender, then deactivate the alias as well if more senders pile onto it.
What if mail still arrives?#
Mail that still arrives after either step usually has a straightforward explanation.
- A blacklist rule is paused. A rule with its toggle off lets mail from that sender through again. Switch the rule back on.
- The wrong block type was used. An Exact Email rule blocks one address only. If the same domain sends from new addresses, switch to an Entire Domain rule or a Pattern rule.
- Subdomains were not included. An Entire Domain rule without Include subdomains checked blocks only the root domain.
- Mail went to a different alias. Check which address the message was sent to, and toggle that alias.
- Mail was sent just before deactivation. Mail already forwarded before the toggle was switched off still arrives. Later mail stops.
- Mail came from an old thread. A reply in an existing thread can look like new mail to an alias. Check the recipient address on the message.
If mail keeps coming to the same deactivated alias well after it was switched off, toggle it on and off once more, then send a test message to it from another address. The test message should bounce.
For wider steps for cutting unwanted mail, including tracing where it came from, see How to stop spam emails.