K-9 / Thunderbird for Android - App Setup




Thunderbird and K-9 Mail app email setup screen on Android

Automatic Account Setup (Recommended)

K-9 Mail and Thunderbird for Android can automatically configure your email account using EZBizMail’s secure Auto-Configuration system. This is the fastest way to set up your email on Android devices.

  1. Install and open K-9 Mail or Thunderbird for Android.
  2. Tap Add Account.
  3. Enter your Email Address and tap Next.
  4. Enter your Email Password and tap Next.
  5. The app will automatically detect and apply the correct server settings.
  6. Confirm the settings and complete the setup.

Once setup completes, your email account is ready to use on your Android device.

Note: Auto-setup requires your domain’s Autodiscover / Autoconfig DNS records to be configured correctly. If automatic setup fails, follow the Manual Setup Instructions below.

Emails stored in your Inbox and Sent folders are automatically retained for 180 days. Other system folders (such as Trash and Spam) are retained for 30 days to help manage disk usage. To keep messages longer, use POP3 to download and save a local copy, or when using IMAP, move messages into a custom folder such as “Saved Email”.

Manual Setup - K-9 / Thunderbird for Android – POP3 or IMAP Setup

Overview

This guide explains how to set up your email account in K-9 Mail / Thunderbird for Android. This app fully supports both POP3 and IMAP with SSL/TLS encryption, and is an excellent choice if you want full control over your email settings on Android.

Replace {YOUR-SERVER-ID} with the server ID shown in your welcome email (for example ez22), and use your full email address such as address@example.com.

POP3 vs IMAP – which should I choose?

  • POP3 (recommended if you want long-term local backups)
    • Downloads messages to your phone and can keep them indefinitely.
    • Uses less server disk space.
    • Ideal if you want a local archive and don’t need full syncing.
    • You can still leave messages on the server for 7–14 days so other devices can download them.
  • IMAP (recommended for multi-device syncing)
    • Keeps mail on the server and synchronizes folders between all your devices.
    • Uses more server storage.
    • What you read, move, or delete on one device is mirrored on the others.

Note: Emails stored in your Inbox and Sent folders are automatically retained for 180 Days and other systems folders (Trash/Spam etc) are retained for 30 days to help manage disk usage. To keep messages longer, use POP3 to download your email and save a local copy or when using IMAP move messages into a custom folder such as “Saved Email”.

Mail server settings

Incoming mail (IMAP)

  • Server (hostname): {YOUR-SERVER-ID}.ourcontrolpanel.com
  • Port: 993
  • Security: SSL/TLS
  • Authentication: Normal password
  • Username: address@example.com

Incoming mail (POP3)

  • Server (hostname): {YOUR-SERVER-ID}.ourcontrolpanel.com
  • Port: 995
  • Security: SSL/TLS
  • Authentication: Normal password
  • Username: address@example.com

Outgoing mail (SMTP)

  • Server (hostname): {YOUR-SERVER-ID}.ourcontrolpanel.com
  • Port: 465
  • Security: SSL/TLS
  • Authentication: Normal password
  • Username: address@example.com

Step 1 – Install and open K-9 / Thunderbird for Android

  1. Open the Google Play Store on your Android device.
  2. Search for “K-9 Mail” or “Thunderbird for Android”.
  3. Install the app and then open it.

Step 2 – Start adding an account

  1. If this is your first time opening the app, the Add Account screen will appear automatically.
  2. If you already have an account, open the menu (≡), go to Settings, then choose Accounts and tap Add account.

Step 3 – Enter your email address and password

  • Email address: address@example.com
  • Password: Your email password

Tap Next to continue.

Step 4 – Choose POP3 or IMAP

You will be prompted to choose the account type:

  • IMAP – for multi-device sync.
  • POP3 – for local archiving and lower server storage usage.

Select your preferred option and tap Next.

Step 5 – Enter incoming server settings

IMAP example

  • IMAP server: {YOUR-SERVER-ID}.ourcontrolpanel.com
  • Security: SSL/TLS
  • Port: 993
  • Username: address@example.com
  • Password: Your email password

POP3 example

  • POP3 server: {YOUR-SERVER-ID}.ourcontrolpanel.com
  • Security: SSL/TLS
  • Port: 995
  • Username: address@example.com
  • Password: Your email password

Step 6 – Enter outgoing (SMTP) server settings

  • SMTP server: {YOUR-SERVER-ID}.ourcontrolpanel.com
  • Security: SSL/TLS
  • Port: 465
  • Require sign-in / Authentication: Enabled
  • Username: address@example.com
  • Password: Your email password

Step 7 – POP3 users: leave messages on the server (7–14 days)

If you chose POP3, you can control how long messages stay on the server:

  1. Open the menu (≡), go to Settings → Accounts and tap your POP3 account.
  2. Look for options such as Fetch mail, Delete from server, or When I delete a message.
  3. Choose a setting that keeps messages on the server for around 7–14 days or until deleted on the device, depending on the options your version provides.

This gives other devices time to download messages while still managing server space.

Step 8 – Finish and test

  1. Tap Next or Done to save your settings.
  2. The app will test the connection and start syncing mail.
  3. Compose a test email to your own address to confirm you can both send and receive messages.

Troubleshooting

  • Cannot connect: Verify that the server name is {YOUR-SERVER-ID}.ourcontrolpanel.com, the port numbers are correct, and SSL/TLS is enabled.
  • Receiving works but sending fails: Confirm SMTP port 465 is selected with SSL/TLS and that authentication is set to Normal password using your full email address.
  • Certificate warnings: Make sure the hostname matches {YOUR-SERVER-ID}.ourcontrolpanel.com before accepting.
  • Mailbox full / quota issues: POP3 with “leave messages on server for 7–14 days” helps reduce server usage while still letting other devices download mail.