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Sign in to Aster Mail

Updated

Sign in to Aster Mail on the web, in the desktop app, or on your phone, and fix the errors that most often stop you.

The same account works everywhere. The web and mobile apps use your password, and the desktop app uses a device code that you approve in a browser.

Before you begin

  • Know the address you registered with. It ends in astermail.org or aster.cx.
  • Have your password ready. Passwords are case sensitive.
  • If you use two-factor authentication, keep your authenticator app, passkey, or backup codes nearby.

Sign in on the web

  1. Go to app.astermail.org. The page is titled Sign in to Aster.
  2. Enter your username and choose your domain.
  3. Enter your password.
  4. To stay signed in on this browser, select Keep me signed in. Leave it off on a shared computer.
  5. Select Sign In.
  6. If Aster asks for a second factor, enter the six-digit code from your authenticator app.

To skip the second factor on this device for the next 30 days, select Trust this device for 30 days before you confirm the code.

Sign in on the desktop app

  1. Open the desktop app. It shows a code under Link this device.
  2. Select Copy code, and then select Open browser.
  3. In the browser, go to app.astermail.org/link-device if it isn’t open, and sign in if Aster asks.
  4. Enter the code, in the format XXXX-XXXX, and select Continue.
  5. Select Use this account, or select Use another account.
  6. Select Link device. When the browser shows “Your desktop app is now linked. You can close this tab,” return to the app.

While it waits, the app shows Listening for confirmation and a countdown next to Expires in. If the code expires, select Get new code and start again.

Sign in on Android or iPhone

  1. Open Aster Mail and select Log in.
  2. On Sign in to Aster, enter your username and password.
  3. Select Sign In.
  4. If Aster asks, confirm your second factor.

For install steps, see Set up Aster on your phone.

Use another two-factor method

When Aster asks for a second factor, you can:

  • Select Use passkey instead to confirm with a passkey. This option appears when your account has a passkey.
  • Select Use a backup code instead and enter one of your backup codes. Each backup code works once.
  • On the backup code screen, select Use authenticator app instead to go back to your codes. On the passkey screen, Use another verification method does the same.

Tips

  • If you use a custom domain, sign in with the astermail.org or aster.cx address you registered with.
  • After five wrong two-factor codes, verification locks for 15 minutes.
  • After 15 wrong passwords, Aster pauses sign-in to your account for 15 minutes. Your mail and settings aren’t affected.

Troubleshooting

  • Incorrect password: check that Caps Lock is off and that the username is right.
  • Aster can’t find the account: check the spelling of your username. If it’s right, select Forgot password? and reset your password.
  • The two-factor code is rejected: a code works only once, and your device clock may have drifted. Turn on automatic time, and then enter the next code.
  • You can’t reach your authenticator: use a backup code or a recovery code, and then set up two-factor authentication again.
  • You forgot your password: select Forgot password? on the sign-in page. Aster sends a reset link to your verified recovery email. See Add a recovery email.
  • Sign-in stopped partway: try again. An interrupted sign-in doesn’t lock your account.

If none of these help, see Recover your account. If you can’t reach your account at all, use the locked-out request form.

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Still need help?

Contact support. Aster replies here and in your inbox.

You can also email hello@astermail.org.