If you are trying to access your Gmail account from the webmail and come across a Temporary Error message, then don’t worry. Gmail Temporary Error means that the mail is currently unavailable. In this case, you just need to sit out for a few minutes and try signing up again after a few minutes. Most probably you should be able to sign up after a few minutes into your Gmail account. However, if the problem persists, then try out the things mentioned below:
First of all, check your network connection and that you are connected to the web.
Try closing the browser and opening it again. Access Gmail.com and try to sign in to your account once again.
Make sure your browser is up to date and if not then update it now.
Clear the stored cache and cookies from your browser.
Add Gmail to the whitelist of your Antivirus or Firewall.
Try using Gmail on Incognito or another browser.
If you’ve recently installed any extensions, try disabling them and then sign in to your account.