Here’s a simple security step that most people overlook: turning off automatic image loading in your email client. It takes about two minutes to set up and closes a real tracking and attack vector.
When your email client automatically loads images, it contacts the sender’s server to fetch them. That server request reveals information about you:
Marketers use this to track open rates, which isn’t always harmful. But spammers and attackers use the same technique to build profiles for targeted phishing campaigns. They combine this data with information from your social media accounts to craft convincing attacks.
Beyond tracking, images can also:
Well-designed emails use ALT text to describe images, so you’ll still understand the content even with images turned off. You can always choose to load images from senders you trust.
To block images by default:
1. Go to File > Options > Trust Center
2. Click Trust Center Settings
3. Check Don’t download pictures automatically in HTML email messages or RSS items
To allow images for a single message:
- Click the InfoBar at the top of the message, then click Download Pictures
To whitelist a sender or domain:
- Right-click a blocked image in a message
- Choose Add Sender to Safe Senders List or Add the Domain to Safe Senders List
To require approval before loading images:
1. Click the gear icon, then See all settings
2. Scroll to the Images section
3. Select Ask before displaying external images
4. Click Save Changes
Gmail already blocks images automatically from senders it flags as suspicious.
To block remote images:
1. Go to Settings > All settings > Proton Mail > Email privacy
2. Turn off Auto Show remote images
To block embedded images:
1. Go to Settings > All settings > Proton Mail > Messages and composing
2. Turn off Auto Show embedded images
When you open an email with blocked images, you’ll see a banner offering to load them. Click Load if you trust the sender.
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