

If your mail app checks for new messages more than once every 10 minutes, the app’s access to your account could be blocked. Make sure your mail app isn't set to check for new email too frequently.In this way, users can change their user interface to another email client for outgoing & incoming emails. For this, you will have detailed information of IMAP, POP3 and SMTP settings. Try signing in directly on the Gmail app. Most of the users want to setup their your Optusnet account in other email clients like Outlook, Apple Mail, Thunderbird, Windows Live Mail, and others. The email client's sign-in method might be insecure.If you recently changed your Gmail password, you might need to re-enter your Gmail account information or completely repeat your Gmail account setup on your other email client.

Allow less secure apps: If you don't use 2-Step Verification, you might need to allow less secure apps to access your account.Important: If you sign in with OAuth, use your regular Google password.Use an App Password: If you use 2-Step Verification, try signing in with an App Password.Update your email client to the latest version.If you have these problems or can’t sign in, first check to make sure you’re using the right password.
