Privacy Policy

Last updated: May 29, 2026

Scope of This Policy This Privacy Policy applies to the mobile application mail4send, developed and published by Küpkodkare Yazılım Ticaret Ltd. Şti.

1. Introduction

Küpkodkare Yazılım Ticaret Ltd. Şti. ("we", "our", or "us") is committed to protecting your privacy. This Privacy Policy explains how mail4send handles information when you use it.

By downloading or using mail4send, you agree to the practices described in this policy.

2. Information We Collect

Information stored locally on your device:

Email account credentials (IMAP/SMTP server address, port, username, and password) — stored only on your device, encrypted using Android Keystore
Email messages downloaded from your mail server via IMAP — stored only locally on your device
App preferences (language, theme, notification settings, signature text, sync frequency)
In-app purchase status (whether ads have been removed, whether a second account has been unlocked)

All of this data is stored exclusively on your device. It is never transmitted to our servers.

Information collected by third-party services:

Google AdMob — used to display advertisements in the free version. AdMob may collect device identifiers and usage data to serve relevant ads. See Google's Privacy Policy.
Google Play Billing — used to process in-app purchases. Purchase data is handled by Google Play. See Google Play's policies.

3. Information We Do NOT Collect

We do not collect, store, upload, or transmit any of your email content, email account credentials, contacts, or personally identifiable information to our servers. We do not operate any backend servers that receive data from our apps. Your emails and credentials remain on your device at all times.

4. Password Security — Android Keystore Encryption

mail4send protects your email account credentials using Android Keystore, Android's hardware-backed security system. Your password is encrypted before being stored on your device. The encryption key is stored in the device's secure hardware module (TEE/HSM) and cannot be accessed by other applications, even on rooted devices.

For Gmail accounts: mail4send requires a Google App Password rather than your regular Google account password. App Passwords are 16-character tokens generated specifically for third-party apps. They can be revoked at any time from your Google account settings without affecting your main password.

5. How Email Deletion Works — Local Only

⚠️ Important — Local Deletion Only: When you delete an email within mail4send, it is removed only from the local list on your device. The email is not deleted from your mail server. Your original email remains completely intact and accessible through your mail provider's web interface, other email clients, or any other device connected to the same account. mail4send does not perform any deletion or modification operations on your mail server.

6. Email Account Credentials and Email Data

mail4send connects directly to your mail provider's IMAP and SMTP servers using the credentials you provide. This connection is established from your device to your mail provider's servers — we are not an intermediary and do not have access to your credentials or email content at any point.

⚠️ Data Loss Disclaimer: mail4send stores downloaded emails locally on your device. Uninstalling the application, clearing app data, performing a factory reset, or any form of device failure may result in the permanent and irreversible loss of locally stored emails. Küpkodkare Yazılım Ticaret Ltd. Şti. is not responsible for any loss of email data regardless of the cause. Always ensure your emails remain accessible through your mail provider's own services.

7. Permissions

Internet — to connect to your IMAP/SMTP mail servers and to display advertisements in the free version.
Access Network State — to check network connectivity before attempting mail synchronization.
Post Notifications (Android 13+) — to display new email notifications.
Receive Boot Completed — to reschedule background email synchronization after device restart.
Foreground Service — to run background mail synchronization reliably.
Read/Write External Storage (Android 12 and below) — to handle email attachments.

8. Advertising

The free version of mail4send displays advertisements served by Google AdMob. You can opt out of personalized advertising: Settings → Google → Ads → Opt out of Ads Personalization. Purchasing the "Remove Ads" option will permanently disable all advertisements.

9. In-App Purchases

Remove Ads — permanently removes all advertisements (non-consumable).
Unlock Second Account — enables adding a second email account (non-consumable).

All transactions are handled securely by Google Play. We do not have access to your payment information.

10. Third-Party Services and Disclaimer

mail4send connects to your email provider's servers on your behalf. We are not responsible for the privacy practices, data handling, security, availability, uptime, or actions of any third-party email providers (Gmail, Outlook, Yahoo, or any IMAP/SMTP server). We encourage you to review your email provider's privacy policy.

11. Limitation of Liability

To the maximum extent permitted by applicable law, Küpkodkare Yazılım Ticaret Ltd. Şti. shall not be liable for:

Loss of locally stored emails due to uninstallation, device failure, or data corruption
Failure to send or receive emails due to mail provider issues or network problems
Security breaches originating from your email provider's servers
Any consequences arising from emails sent or received through the app
Service interruptions caused by third-party mail servers
Any data loss arising from bugs, crashes, or unexpected application behavior
Emails deleted from the local list that are still present on the mail server

12. Data Retention and Deletion

All data stored by mail4send is retained on your device until you uninstall the application or clear the app's data through Android settings. We do not retain any data on our servers because we do not collect any.

13. Children's Privacy

mail4send is intended for general use. Since we do not operate backend servers, no personal data is transmitted to or stored by us at any time.

14. Changes to This Policy

We may update this Privacy Policy from time to time. Changes will be reflected by updating the "Last updated" date at the top of this page.