How to fix slow email opening on 2015 iMac?

Who is your eMail provider & ISP?

Mail and Google's OAuth 2.0 policy

Mail and Google's OAuth 2.0 policy - Apple Community

Fix…

https://code2care.org/macos/fix-mail-authorization-error-400-invalid-request/

Mac's Mail App is not as modern as iOS's Mail app, Many eMail providers now require a separate App Password different from your eMail password…

If it's an IMAP account, delete it in Sys Prefs Internet Accounts then use "Other" instead of gMail choice to add it.

Most likely biggest factor is using Other in Mail setup, then using a Browser that doesn’t have gMail PW stored init to get the App PW.

https://discussions.apple.com/thread/255332568?answerId=259925986022&sortBy=oldest_first#259925986022

Thanks to Bob Sabiston…

iMac says Connection Insecure. Failed to … - Apple Community

Thanks to Webmb…

Sonoma can’t connect to gMail…

I'm no longer receiving mails on my iMac … - Apple Community

GC mac

User level:

Level 1

4 points

Nov 1, 2023 10:12 PM in response to Maggiellv

I also spent hours trying to solve this issue until I followed this video... It worked and my Gmail accounts are back on Mac Mail.

Give it a shot and good luck! https://www.youtube.com/watch?v=U0WPw2TsTAY

It might just need an App Password separate from the gMail password…

The process to add a gmail account to my … - Apple Community

https://support.google.com/a/answer/9003945?hl=en#apple-mail&zippy=%2Cset-up-gmail-with-mail-on-a-mac

Can't add a Gmail account to Apple Mail - Apple Community

Thanks,

reate a secure mail key

It’s easy to create a secure mail key from your mobile device, tablet, or computer. Have your User ID and password ready to sign in to myAT&T.

1. Go to your myAT&T Profile. Sign in, if asked.
2. Scroll to My linked accounts, select the email account that needs a secure mail key.
3. Scroll to Secure mail key, select Manage secure mail key.
4. Choose the email address that you’d like to use, if you have more than one.
5. Select Add secure mail key. Enter a nickname for the secure mail key to make it easy to recognize.
6. Choose Create secure mail key.
7. Select Copy secure mail key to clipboard. Make a note of your secure mail key for further updates.

• • For security purposes, the secure mail key only displays until you select OK. 
  • If you lose or forget the secure mail key, you can always create new secure mail keys.

1. Select OK.
2. Go to your preferred email app, replace the existing password with your secure mail key. For an IMAP account, delete the existing password for both the IMAP and SMTP servers. Replace them with your secure mail key.

Good to know: Each device you use to access your email will have its own secure mail key.

https://www.att.com/support/article/email-support/KM1240308/