# Settings

How to customize your store, newsletters, and integrations

- [Letterhead's Recipient Validation](https://help.tryletterhead.com/letterhead-recipient-validation)

## Account Management

- [How can I find my Organization's API Key?](https://help.tryletterhead.com/api-key-management)
- [How Do I Add a Team Member to Letterhead?](https://help.tryletterhead.com/add-team-member)
- [How to Reset Your Password](https://help.tryletterhead.com/how-to-reset-your-password)

## Domain Management

- [What is BIMI and How to Set It Up](https://help.tryletterhead.com/what-is-bimi-and-how-to-set-it-up)
- [How do you opt-out of double opt-ins?](https://help.tryletterhead.com/opt-in)
- [How do I set up my custom sending domain for my organization or my channel?](https://help.tryletterhead.com/sending-domain-configuration)