Privacy

Your email is yours. How Lumen Mail handles your data — in plain language.

Nothing is sent without you

The AI proposes drafts and actions, but sending always depends on your confirmation. No email leaves your account automatically.

Personalized model, not collective

Prioritization learns from your usage, in your own profile. We don't train a global model on the aggregated data of all users.

On-device by default

Embeddings and the search index are built on your iPhone. The raw content of your emails doesn't need to be vectorized remotely.

Minimum necessary, no retention

What goes to the cloud is only what's essential to classify, draft, and synthesize — discarded after the response, never stored for training.

What data we collect

To connect your account, we store Gmail OAuth access tokens on your device. For the AI features, we temporarily process the content of the specific emails you choose to act on — to classify importance, generate a draft, or answer a search. Usage metadata helps improve prioritization within your own profile.

How we use AI

Prioritization combines signals such as frequent senders, deadlines, direct questions, and your reply history. Voice drafts use samples from your own sent emails so they sound like you. Semantic search retrieves relevant passages on-device and uses an LLM only to synthesize the final answer, always citing the source.

Third-party sharing

LLM providers process data under a no-training agreement, following Google Workspace API's Limited Use model. We don't sell your data or use it for advertising. There's no sharing beyond what's strictly necessary to operate the features you trigger.

Retention and deletion

Cloud processing is ephemeral: discarded as soon as the response is delivered. The search index, tokens, and preferences live on your device and are erased when you disconnect the account or remove the app. You can revoke Lumen Mail's access at any time from your Google account.

Your rights

You can disconnect accounts, delete the local index, and review exactly which data lives where, right in the app under Account & settings › Privacy and data. Requests related to personal data can be sent to our privacy contact.

Last updated: July 2026.