What’s “policy quarantine” in some regional ISPs?

Understanding policy quarantine:

What it is:

Mail held in limbo rather than delivered or bounced

May be reviewed by postmaster or automatically processed later

Neither immediate delivery nor clear rejection

Why ISPs use it:

Uncertainty about sender legitimacy

Allows manual review of suspicious patterns

Reduces risk of blocking legitimate mail

Symptoms:

No bounce, but no delivery

Mail appears lost

Delayed delivery (hours or days later)

Regional variations:

Some regional ISPs have unique quarantine policies

Less standardized than major providers

May require direct contact to resolve

Cargo held in customs inspection. Not cleared, not rejected, just waiting.