When people think about email privacy they picture message contents: an attacker reading a draft, a provider scanning for keywords. Content matters, but it is rarely the most revealing part of a message.
What metadata exposes
Every email carries headers: sender, recipients, timestamps, the chain of servers that handled it, and often the client software used. Collected over weeks, that record describes a social graph, a daily routine and an employer without a single message body being read.
Received: from mail.example.org (mail.example.org [203.0.113.7])
by mx.example.net with ESMTPS (TLS1.3)
Date: Tue, 14 Oct 2026 09:14:02 +0000
From: alice@example.org
To: bob@example.net
Subject: ThursdayNotice what is visible even if the body is PGP-encrypted: both addresses, the exact time, the subject line, and the route.
What you can actually do
- Keep subjects bland. PGP does not encrypt the subject in most clients.
- Use aliases so that unrelated services cannot join your identities together.
- Block remote content. Tracking pixels report when and where you opened a message.
- Prefer fewer hops. Mail between two accounts on the same host never crosses the open internet.
Encryption protects what you said. Habits protect who you said it to.
No provider can erase metadata completely, because mail servers need it to deliver messages. The realistic goal is to reduce it, keep it short-lived and avoid handing it to anyone with a commercial interest in it.