LinuxSecurity.com

If you manage Linux systems long enough, you start to notice that most security conversations are not really about attackers or tools. They are about pressure. Uptime targets that do not move. Patch windows that keep shrinking. Audits that ask for proof you did the right thing six months ago. Incidents that blur together because the alerts never quite stop.

Email still looks like plumbing until it becomes the incident timeline, which is why the enterprise email security decision tends to surface only after something slips through and everyone is suddenly counting minutes. By then, the question is no longer about preference or tooling taste; it is about whether the system bends under pressure or holds.

Perimeter-based email security assumes mail reliably passes a single inspection point. That's how most Linux mail stacks were designed to operate: one choke point in front of the MTA, one place to enforce policy, one place to log what happened. In cloud environments, that stops being true fast. Some mail hits the gateway, some go directly to the tenant, and internal messages often bypass it entirely.