How to fix Galaxy S8 “invalid email address” error when sending emails

This troubleshooting article talks about fixing Galaxy S8 “invalid email address” error. This bug seems to appear only when an S8 tries to send an email, as detailed by a user below. If you encounter the same problem, find out the steps below on how to deal with it.

Problem: Galaxy S8 “invalid email address” error when sending emails

galaxy s8 was hacked. problems were, screen shut down about as fast as I could turn on device, could not turn device off, screen was locked, couldn’t access. had help bypassing locked screen. rebooted device losing pics. everything seemed to be ok until I tried to send email. every address I enter says “invalid email address”. when I try to put my email address in like registering somewhere, message says invalid email address. I can receive emails ok. have searched on line for days, cant find solution. have tried enter google account, can’t access. they have sent numerous verification codes. when I input code, message says wrong code.  can’t find help from google. if not a phone issue, any ideas on what to do next? THANKS.

Solution: “Invalid email address” error is generic and does not usually point to any specific factor. In order to know the real reason for it, you must perform a number of troubleshooting steps. Follow the steps below on how to do it.

Wipe the phone

If you suspect that your phone had been hacked, the first thing that you need to do is ensure that it’s restored to its factory state. You can do that by wiping it with factory reset. Follow the steps below on how to do that:

  1. Create a backup of your photos, videos, contacts, documents, etc.
  2. Turn off the device.
  3. Press and hold the Volume Up key and the Bixby key, then press and hold the Power key.
  4. When the green Android logo displays, release all keys (‘Installing system update’ will show for about 30 – 60 seconds before showing the Android system recovery menu options).
  5. Press the Volume down key several times to highlight ‘wipe data / factory reset’.
  6. Press Power button to select.
  7. Press the Volume down key until ‘Yes — delete all user data’ is highlighted.
  8. Press Power button to select and start the master reset.
  9. When the master reset is complete, ‘Reboot system now’ is highlighted.
  10. Press the Power key to restart the device.

Set up email

Once the phone has been wiped via factory reset, the next good thing to do is to set up your email again. You need to do this before installing any of your apps back. This should eliminate the chance of a third party app interfering with your email.

When setting up your email, make sure that you use the correct incoming and outgoing server types. Refer to your email provider’s instructions how to add your email properly.

After the setup, you then want to check again if the problem is gone. If “invalid email address” error goes away at this time, you can then go ahead and install your apps back.

Boot to Safe Mode

If “invalid email address” error returns after installing your apps back, that’s a clear sign that one of them must be source of the bug. It’s also possible that it may be the same reason for the hacking incident. To check if you’ve installed a bad app, consider booting it to safe mode. On this mode, all downloaded apps will be blocked from running, giving you an option to identify the culprit later on. To boot to safe mode:

  1. Turn the device off.
  2. Press and hold the Power key past the model name screen.
  3. When “SAMSUNG” appears on the screen, release the Power key.
  4. Immediately after releasing the Power key, press and hold the Volume down key.
  5. Continue to hold the Volume down key until the device finishes restarting.
  6. Safe mode will display in the bottom left corner of the screen.
  7. Release the Volume down key when you see Safe Mode.

Once the device has been restarted to Safe mode, you then want to check if email starts working fine again. If it goes well and the “invalid email address” error won’t return, you must do a follow up process of identifying the bad app. Here’s how to do that:

  1. Boot to safe mode.
  2. Check if “invalid email address” error returns. If email works fine, go ahead to Step 3.
  3. Uninstall an app that you think might be the cause of the problem.
  4. After you uninstall an app, restart the phone to normal mode and check for the problem.
  5. If “invalid email address” error returns, repeat steps 1-4.

Check if email can send on webmail

If the error persists even on safe mode, it means that the cause of the problem is not a third party app. It may be a glitch with your email account. To check if that’s the case, try sending an email using a web browser. Any browser will do so it’s up to you. The aim of this troubleshooting step is to check whether or not your email account is having an issue sending an email.

Clear email app cache

If there’s no problem sending an email on webmail, then you should go back to troubleshooting the email app. One of the direct ways to deal with the app is by clearing its cache. Here’s how:

  1. Open Settings app.
  2. Tap Apps.
  3. Tap on More settings at the upper right (three-dot icon).
  4. Select Show system apps.
  5. Find and tap your app.
  6. Tap Storage.
  7. Tap Clear Cache button.
  8. Restart your S8 and check for the problem.

Clear email app data

Should nothing work after clearing the email app’s cache, try returning the app to its factory state. Follow these steps:

  1. Open Settings app.
  2. Tap Apps.
  3. Tap on More settings at the upper right (three-dot icon).
  4. Select Show system apps.
  5. Find and tap your app.
  6. Tap Storage.
  7. Tap Clear data button.
  8. Restart your S8 and check for the problem.

Use another email app

In case the problem is caused by a bug within the email app itself, consider using a different email app. We assume you’re using the stock Samsung email app so you can pick others such as Google’s Gmail app, Microsoft’s Outlook, or any other app in the Play Store.