How do I update a gmail password in macOS Mail

You are right. Thank you for correcting me. I personally no longer use Mail, so I thought I remembered it as being like other email apps I've used. Mail's email passwords are accessed by following steps.

• Open Mail
• Click on the settings link under the Mail menu
• That opens a window where the email apps accounts are listed. Be sure that you have the right one selected.
• Next, click on the Server Settings button at the top of the window.
• This is where incoming and outgoing passwords can be accessed down below. At this point they are blocked and a series of dots are displayed.
• To display passwords click in the password window. This will open a small window which says Passwords.... Click on it.
• Next opens a window which says 'Passwords Are Locked'. You are then asked to enter your Mac's password which will unlock access to them.
• This opens a window where you will see items listed from from Keychain's menu.
• Scroll down to the line that lists your email account and click on it. Then click on the Fill button.
• If you have selected the correct line, the password will be filled in.

As you can see, this is an involved process. That is one reason why I no longer use Mail. It is problematic and sometimes difficult.

The easiest way is to delete the account from your device and add it back with the new credentials. It will be far less frustrating than trying to edit the password. That rarely works.

1 - Go to Google Mail online and sign in. Google Accounts: Sign in

2 - click on Security

3 - click on Password

4 - sign in again.

5 - follow instructions to reset the password

The way to update your password in Mail (or most any email) app is done in Mail's preferences.