For those of you who are very concerned with the security of your Email Client, the 'Auto Download Image' configuration can be something you should also pay attention to. Although not the main focus, this setting can also help keep your Email Client safe from spam emails, phishing, or similar threats.
Is the 'Auto Download Image' configuration important in Email Client?
Although rare, some senders that are flagged as spam or phishing might embed scripts in images in the emails you receive. Then these spammers can send emails to you again. This is certainly quite dangerous.
However, as long as the Email Client does not have a critical bug, this case rarely occurs.
But if you still want to disable the Auto Download Image setting, here are the steps you can take:
Outlook (Mail Outlook for Windows 10)
Click the Settings icon.
Select 'Reading Pane'.
Under 'External Content', disable the option 'Automatically download external images and style formats except S/MIME Mail'.
Outlook (Browser Version)
Click the 'Settings' icon.
Select 'Mail', then 'Layout'.
Find the 'Sender Image' setting, then select the option 'Don't show sender images'.
Gmail
Click the 'Settings' icon, then select 'See All Settings'.
In the 'General' tab, find the 'Images' setting.
Select 'Ask before displaying external images'.
Once you have configured the 'Auto Download Images' settings, whenever you receive an email, a notification will appear asking for permission to download the images or not.