Blocking moves that sender's mail to junk. It does not tell them to stop, does not delete you from their list, and does not survive them changing address. It's a useful tool for a specific case — a persistent sender you've identified — and close to useless against bulk operations that rotate addresses. Block the domain rather than the address, and understand what it can't reach.
What blocking actually does
Blocking is a rule in your mail account. The sender is not notified, their system records nothing, and their next message is still accepted by your mail provider and delivered — just into the junk folder rather than the inbox.
That distinction matters because it explains every limitation below. You've changed where mail lands, not whether it's sent.
How to block, per provider
- Gmail: open the message → overflow menu → Block "sender". Future mail goes to Spam.
- Outlook: Junk → Block, or add the address or
@domainto Blocked Senders in settings. - Apple Mail / iCloud: tap the sender → Block this Contact.
- Any provider: a filter or rule matching the sender domain is more durable than the built-in block, because it can match a whole domain and take a stronger action.
The four things blocking can't do
- It doesn't stop sending. The sender keeps mailing; you just don't see it. Nothing signals to them that the address is unwanted.
- It doesn't survive address rotation. Bulk senders change the local part constantly —
promo-47@becomespromo-48@. Blocking one address is a single skirmish in a war of attrition. - It doesn't remove you from lists. Your address stays in their database and in the databases of anyone they shared it with.
- It's per-account. Blocking in Gmail does nothing for the same sender reaching a different address of yours.
Block by domain
This is the single change that makes blocking meaningfully better. Instead of blocking newsletter@example.com, block @example.com — or write a rule matching from:(*@example.com).
Rotation happens before the @, not after it, so a domain block survives it. The exception is operators who also rotate domains, which is common for outright fraudulent mail — at which point blocking stops being the right tool and reporting is.
Block, unsubscribe, or disable?
| Situation | Best move |
|---|---|
| Legitimate company, too much mail | Unsubscribe. Legally required to be honoured, and stops it at source. |
| Legitimate company, ignored your opt-out | Block, then report. Escalation path |
| Outright spam, rotating addresses | Report as spam. Blocking individually is unwinnable. |
| One persistent known sender | Block the domain, or write a rule. |
| Mail arriving at an address you gave one company | Disable that address. Nothing to block, and the sender gets a real rejection. |
That last row is the qualitative difference. Blocking is a rule about what your inbox accepts. Disabling an alias removes the route entirely — the sending server is told the address doesn't accept mail, which mailing platforms treat as a reason to suppress it. What that does in detail.
More: less spam in Gmail · less spam in Outlook · the full guide