# The from-address rules that 403 you

Two knowledge-base pages cover this, and together they explain almost every
first-send 403:

1. The test address only sends to yourself. Emails from the default test
   address can only go to your own email address. Sending to anyone else gets a
   403 telling you to verify a domain and change the from address.
2. Any other from domain must be verified. If the domain in your from address
   does not match a verified domain on your account, the API returns a 403
   domain-mismatch error.

## Checklist

- Before writing any send code, verify the domain in the dashboard and set the
  from address to an address on it. Doing this after the code is written turns
  a two-minute setup step into a debugging session.
- When a send 403s, read the error: test-address-to-stranger vs unverified
  domain are different fixes. The error text names which one.
- The to address matters too during testing: with the test from address, keep
  recipients to your own address until the domain is verified.
- Deliverability starts here as well: a verified domain with proper DNS is
  what keeps the email out of spam.