Privacy policy

Effective October 29, 2026

Zilch is a private email client for Mac, iPhone, Apple Watch and privately paired browsers. Promeddevs, LLC develops Zilch. This policy explains how the app handles information and how to contact us.

Information the app accesses

When you connect an email account, Zilch can access account identifiers and addresses, message headers, senders and recipients, subjects, message bodies, attachments, folders or labels, and read or archived state. It also stores the drafts, preferences, rules, templates, reminders and contact associations you create.

Google account access and permissions

Google authorization provides tokens that let Zilch work with the Gmail account you select. The Mac and browser mail engine uses Gmail's full mail permission for IMAP/SMTP access. The native iPhone client requests Gmail modify permission for reading and organizing mail and sending your replies. Google displays the permissions before you authorize access.

These permissions support reading, searching and displaying messages and attachments; organizing Inbox, Digest and Archived; changing labels and read state; and sending email that you choose to send. Enabled filing rules can organize mail automatically. Scheduling a reply authorizes its later send. Connecting an account by itself does not authorize Zilch to send arbitrary messages.

How information is used

Zilch uses email information to provide the email features you choose, including conversation grouping, mail search, filing, notifications, drafts and replies. Sender rules and preferences help organize future messages. Zilch does not sell Google user data or use it to serve advertising.

Storage and connections between devices

Saved mail and attachments are cached on the devices or Mac mail engine you use. Credentials and authorization tokens are stored using the app's local credential protection. Device security, storage protection and backups also depend on your operating system and configuration.

When enabled, private iCloud synchronization carries supported drafts, rules, templates, preferences, reminders and related settings between your devices. It does not synchronize the mail-provider credential store or the complete mailbox cache through that settings mechanism. iPhone shares mailbox views, messages and selected media with your paired Watch. Privately paired browsers communicate with your Mac mail engine over HTTPS using a separate device session.

Optional AI assistance and other services

AI assistance requires an explicit sharing choice in Zilch. If enabled, information needed for the requested feature can be sent to the AI service you select, such as OpenAI's API or a ChatGPT connection you authorize. This can include sender or recipient details, subjects, email excerpts, conversation context, instructions, reference material and draft text. The selected provider processes submitted information under its applicable terms and data controls. Review those controls before enabling AI processing.

You can turn off sharing and disconnect the AI provider in Settings. Manual email features remain available. Zilch's API requests specify that generated responses should not be stored by the Responses API, but that setting is not a promise of zero provider logging or retention. Zilch does not itself train general-purpose AI models on your email.

Google provides Gmail authentication and email services. Apple supplies device, iCloud and Watch communication features where used. Opening a link in an email may communicate with that link's website under its own privacy policy. This informational site is hosted through ChatGPT Sites infrastructure; routine hosting requests may include technical information such as an IP address and browser headers. We have not added advertising or analytics scripts to this site.

Google API user-data policy

Zilch's access to and use of information received from Google APIs is limited to the email features and user-directed processing described above and is subject to the Google API Services User Data Policy, including its Limited Use requirements. Google user data must not be used for advertising, resale or training general-purpose models. Enabling an optional connection does not remove those restrictions.

Retention, deletion and revoking access

Mail, drafts, attachments and settings can remain in the app's local storage while you use it. Cached information may also exist on your other devices or in backups. Archiving preserves email; it is not deletion. Removing an account or revoking Google authorization stops future access but may not remove previously saved copies, device caches or backups.

You can manage or remove accounts in Zilch and revoke its Google access from your Google Account connections. Use the relevant device and backup controls to remove retained local copies. For information you directly send to our support address, contact us to request access or deletion. Third-party providers manage copies they hold under their own policies.

Support and human access

Promeddevs does not receive a copy of your mailbox through this public website. If you choose to send support messages, logs, screenshots or sample emails, we can use those materials to respond to your request. Do not send account passwords or authorization tokens to support.

Contact and policy updates

For privacy questions or requests, email info@promeddevs.com and identify Zilch. We may update this policy as the app changes and will revise its effective date. Material new data sharing requires the applicable in-app choice or authorization.