Auto-reply

Auto-reply sends an automatic response to incoming email. Use it for vacation notices, out-of-office messages, or any time you want senders to know you are unavailable.

How it works

When auto-reply is enabled on a mailbox, every inbound email receives the configured reply. Stalwart handles delivery at the mail server level, so replies go out immediately without any additional API calls.

Each sender receives at most one auto-reply per day to avoid flooding their inbox.

Enabling auto-reply

Go to the Mailboxes page.
Click the mailbox you want to configure, then open the Auto-reply tab.
Toggle auto-reply on, write your message, and optionally set start and end dates.
Click Save. The mailbox row will show an Auto-reply badge.

Date scheduling

You can set optional from and to dates. When both are set, the auto-reply is only active during that window. Outside the window the mailbox behaves normally. If no dates are set, the auto-reply stays active until you disable it manually.

API

Use the PATCH /v1/mailboxes/:id/auto-reply endpoint to configure auto-reply programmatically. See the Mailboxes API reference for details.

curl -X PATCH https://shipmail.to/api/v1/mailboxes/mbx_abc123/auto-reply \
  -H "Authorization: Bearer sm_live_..." \
  -H "Content-Type: application/json" \
  -d '{
    "enabled": true,
    "body": "I am away until January 6. I will reply when I return.",
    "from_date": "2026-12-23T00:00:00Z",
    "to_date": "2027-01-06T00:00:00Z"
  }'

Disabling auto-reply

Toggle it off in the dashboard, or send a PATCH request with {"enabled": false}. The saved message and dates are cleared.

Limitations

Auto-reply message is plain text only (no HTML).
Maximum message length is 5,000 characters.
Each sender receives at most one auto-reply per day per mailbox.
Suspended mailboxes do not send auto-replies. Auto-reply settings are restored when the mailbox is unsuspended.