Good evening, @HTE2006. 

Thanks for joining the QuickBooks Community. I hope you're having a wonderful day so far. 

As of May 30th, Google changed the sign-in process and no longer supports sign-ins by user name and password. During this change, it affected sending transactions, etc., in QuickBooks. I've included some steps below to resolve this matter. 

You'll need to change your Gmail account to use the secure webmail. Here's how: 

1. Turn on 2-step verification for your Google account.
2. In QuickBooks, select Edit and then select Preferences.
3. Tap on Send Forms.
4. Click WebMail.
5. Select your Gmail User Id and Edit.
6. Tap Use enhanced security and select OK. We’ll also ask you to sign in to your Intuit account to complete the process.
7. Your Gmail sign-in page will display. Sign in and grant Intuit access.

For additional details about the change, check out Set up enhanced security in Gmail for QuickBooks Desktop. 

Please don't hesitate to let me know if you have any questions or concerns. Take care, and have a great weekend! 

Hello there, HTE2006.

This will prevent the browser in blocking site content. Furthermore, always use a supported and up-to-date browser.

Here's how to add Intuit:

Safari

1. Open Safari, then enter payroll.intuit.com
2. Choose Enter.
3. Select Bookmarks and select Add Bookmark.
4. From the drop-down, under Add this page to select Top Sites.
5. Select Add.

Google Chrome

1. Select the Customize and control Google Chrome ⋮ icon and choose Settings.
2. Scroll down to the bottom and select Advanced.
3. In the Privacy and security section, select Site Settings.
4. Select Cookies.
5. In the Allow section, select Add.
6. Enter *intuit.com, then select Add to save.

Also, any app accessing Google data needs to be reauthorized as part of the updated Google's privacy policy. This means we need to authorize QuickBooks to use Gmail. Before doing so, ensure that your QuickBooks Desktop (QBDT) is updated to its latest release version.

After that, refer to this article and proceed to How to authorize QuickBooks Desktop to use Gmail section for further guidance: Reauthorize QuickBooks Desktop to keep using Gmail.

Once done, let's set up your Gmail again in QBDT. Here's how:

1. Go to the Edit on the top menu to get to the Preferences.
2. Select Send forms at the left pane and proceed to the My Preferences tab.
3. Choose WebMail, then tick the Add option below.
4. Enter your email address in the Email Id field and select Gmail from the Email Provider drop-down.
5. Hit OK.

For more details about connecting your email into QuickBooks, please refer to this article: Connect your email to QuickBooks Desktop.

For more troubleshooting steps about this error, you can read this article: Gmail couldn’t sign you in from QuickBooks Desktop.

To add up here are some links that you can visit about fixing its error in QuickBooks Desktop for reference: Fix Error: Could not connect to the email server
 

Let me know how it goes, I'll be around if you need more help.