load content directly using macOS Sequoia 15.3

From Apple:

Use Mail Privacy Protection on Mac

The Mail app can help protect your privacy. Email messages you receive may include remote content that allows a sender to collect information when you view a message, such as when and how many times you view it, whether you forward it, your IP address, and other data. Mail Privacy Protection prevents senders from learning your information.

If you didn’t turn on Protect Mail Activity when you first opened Mail (macOS 13 or later), you can do so in Mail settings.

1. Go to the Mail app  on your Mac.
2. Choose Mail > Settings, then click Privacy.
3. Select Protect Mail Activity.
4. When this option is selected, your IP address is hidden from senders and remote content is privately downloaded in the background when you receive a message (instead of when you view it).
5. If you deselect the option, you can choose to separately hide your IP address and block all remote content. When Block All Remote Content is selected, a banner is shown in a message when you view it, indicating it contains remote content; you can choose then to download the content.

Use Mail Privacy Protection on Mac - Apple Support

Tracy Brown1 wrote:

After I did the update to macOS Sequoia 15.3 the content in my email no longer downloads directly. To download the content I keep having to go to the "load content directly" button on the top right of my email messages. Do you know how to fix this so that it automatically downloads again?

Open Mail.app from the menu bar select Mail>Settings>Privacy and disable all and compare your results:

Protect Mail Activity

Hide IP address

Block all remote content