Hi every so often when I go to check my e-mail it say can't sign in I've not changed my password, why does it keep doing this ?
If you're using a Samsung default email app, you can try removing the email and adding it again.
Please head to Settings > Clouds and accounts > Accounts > tap your emai > (remove and re-add).
If you're using a web browser like Samsung Internet browser, Google Chrome or other web browser to open your email, you may try other web browsers that are not in use (or if you could download one), if the error persists, please contact your email provider, this could be their server error.
Thank you ^_^