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Add +receipts, +newsletters, or +travel to your hosted address to organize mail without creating another inbox. For example, mail to [email protected] arrives in the [email protected] mailbox.
Plus aliases are available when enabled for your hosted mailbox. They do not extend to custom-domain or connected inboxes. Aliases use your current hosted address; changing the mailbox address does not keep an old address active.
Valid aliases work without setup. They share the parent mailbox’s storage, permissions, sending limits, and billing. Saving an alias only creates a shortcut.

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Save and share an alias

  1. Open your mailbox’s Settings, then find Aliases.
  2. Enter a tag such as receipts in Alias tag. Check the full-address preview.
  3. Optionally enter a Label, then click Save alias.
  4. Click Copy address and use that address with the service sending you mail.
Tags accept 1–32 letters, numbers, dots, underscores, or hyphens. Start and end with a letter or number. Tags are normalized to lowercase. Do not include another + separator. The complete address must also fit email address length limits.

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Find mail for an alias

Click View mail beside an alias to open its inbox filter. Incoming messages with verified alias delivery information show an alias badge. You can also save an observed alias from message details. Filtering uses the actual delivery address, independently of visible To and Cc headers. This supports Bcc delivery and avoids treating a spoofed To header as proof that a message arrived through an alias. Older messages without verified delivery information do not match an alias filter.

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Send and reply

New messages default to your primary address. In From, choose a saved alias or enter another valid full alias address belonging to the same mailbox. Replies default to the original delivery alias when verified information is available, including AI-generated replies. Reply-all excludes your mailbox’s own alias addresses. Drafts and scheduled sends retain the selected sender. If an alias is blocked before submission, sending stops with an error. Unblock the alias or edit the sender before retrying; Mermail does not silently substitute the primary address.

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Create an alias-specific routine

Click Create routine beside the alias. The editor opens with its recipient alias constraint filled in. Complete the routine’s instructions and other conditions, then save it through the normal editor flow. The recipientAlias constraint matches the normalized tag exactly against verified delivery information. It must match even when other content conditions use OR logic. Existing routines without this constraint continue to match as before. Marketplace inboxes retain their automation restrictions.

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Block or unblock an alias

Click Block beside the alias and review the confirmation. Blocking:
  • Discards future incoming mail to that alias.
  • Stops sending from that alias, including pending scheduled sends.
  • Keeps existing messages and routine settings.
Click Unblock to restore delivery and sending eligibility. Configured routines can match future eligible deliveries again. Discarded mail is not restored. Remove shortcut only removes the saved shortcut. It does not stop delivery or remove an existing block. Use Block when you want mail to stop.

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Use the API or MCP

Use the alias endpoints and MCP tools to list, save, update, or remove shortcuts. Listing requires mailbox read access; changes require mailbox settings administration permission. For example, save a shortcut with the following request body:
Keep using the existing email from field for sending. Set it to the full address, such as [email protected]. Saving the alias first is optional. Authorized message responses can include delivery_address. Treat a null value as unavailable delivery information; do not reconstruct it from To/Cc headers. See Mailboxes for the API operations and Email module for delivery status and sending limits.