If your sent mails are failing to reach their destination and are instead sent to Outbox, then you should be checking the info in this post and learn how to fix it.
If some of your e-mails are sent to Outbox, then something might be wrong with the app's synchronization to your Google account, or something went wrong with the Gmail servers. Note that the problem you are encountering might also be due to a loss of signal or some other network connectivity issue.
Before trying to apply any of the changes listed below you should open the Gmail website on your computer, and see if the emails are sent when you're doing it from the PC. In care there no issues sending an e-mail via Gmail when using the PC, then something is surely wrong with your Galaxy S8 device.
Note that some of the steps below might require you to wipe some data, so you should only apply them if you are an advanced user.
How to fix Gmail and stop it from sending e-mails to Outbox:
If your Gmail app fails to successfully send any emails to their intended targets, then you will have to check the instructions below and learn how to fix the issue.
Verify Internet Connection and make sure it works:
If you know that you have trouble sending e-mails via Gmail, then you should first check the internet connection and make sure that it is working. Try to use Wi-Fi first to send your e-mails, and then use the mobile data in case the Wi-Fi has failed. If both connections aren't working for your Gmail app, then you should reboot the phone.
After the reboot is done you simply have to retry sending the email.
Clear Gmail app cache and app data:
The emails not being sent might also be due to some Gmail app local problem, so you should try to clear the app data and reset it. Here's how to do it:
- go to Settings.
- open Apps.
- find the Gmail app in the list and open the app system settings.
- go to Storage now.
- tap the "clear cache" option and confirm.
- next, tap "clear data" and confirm this process, too.
- go back into Gmail and re-login using your default Gmail account.
- try to send an email and test the issue.
If the problem has been fixed by this guide, then you are done and we kindly ask you tell us in comments if it did, so that others will find it easier to learn how to repair their Gmail app.
In case you need any extra help completing this guide, or you can think of other methods that can be used to fix the Gmail not sending e-mails issue, then you can tell us below.