Sender rules let you control who can send email to your inboxes. You can block specific senders or domains, or switch to allowlist mode so only approved senders get through.
How it works
Every inbound email is checked against your sender rules before delivery. Rules match on either a full email address (user@example.com) or an entire domain (example.com).
There are two rule types:
| Type | Effect |
|---|
block | Emails from this sender or domain are silently dropped |
allow | Used in allowlist mode — only these senders get through |
Filter modes
Your account has an inbound filter mode that controls how rules are applied:
| Mode | Behavior |
|---|
none (default) | All inbound email is accepted. Block rules still apply. |
allowlist | Only senders matching an allow rule are accepted. Everything else is dropped. |
Default mode (none)
In default mode, all inbound email is delivered unless the sender matches a block rule. Use this when you only need to block a few known bad senders.
Allowlist mode
In allowlist mode, only senders that match an allow rule are delivered. All other email is dropped. Use this when your agent should only communicate with a known set of contacts.
Block rules are always enforced, even in allowlist mode. If a sender matches both an allow rule and a block rule, the block rule wins.
Rule matching
Rules match against the sender’s email address (From header):
- Email rules match the exact address:
spam@example.com
- Domain rules match any address at that domain:
example.com blocks alice@example.com, bob@example.com, etc.
Values are case-insensitive and normalized to lowercase.
Managing rules
You can manage sender rules from the Allow/Block List page in your Dashboard settings. From there you can:
- Add email addresses or domains to your allow or block list
- Switch between
none and allowlist filter modes
- Remove rules you no longer need
What happens to filtered email
Emails that are blocked or not in the allowlist are silently dropped. They do not trigger webhook or WebSocket events, and they do not appear in your inbox.
Sender rules work alongside suppressions. Suppressions automatically block addresses that have bounced or been reported as spam. Sender rules give you manual control on top of that. 
