---
name: "qmail-popup"
section: "8"
platform: "linux"
package: "qmail"
version: "1.06-6.2~deb10u1"
release: "Debian 10 (Buster)"
platforms: ["linux"]
url: "https://new.carta.tech/qmail-popup"
---

# qmail-popup(8)

read a POP username and password

## NAME

qmail-popup - read a POP username and password

## SYNOPSIS

**qmail-popup** *hostname* *subprogram*

## DESCRIPTION

**qmail-popup** reads a POP username and password from the network. It then runs *subprogram*.

**qmail-popup** is most commonly invoked from **inetd** as

```
   qmail-popup CHANGEME checkpassword qmail-pop3d Maildir
```

with CHANGEME replaced by the fully qualified domain name of the local host.

**qmail-popup** expects descriptor 0 to read from the network and descriptor 1 to write to the network. It reads a username and password from descriptor 0 in POP's USER-PASS style or APOP style. It invokes *subprogram*, with the same descriptors 0 and 1; descriptor 2 writing to the network; and descriptor 3 reading the username, a 0 byte, the password, another 0 byte,  an APOP timestamp derived from *hostname*, and a final 0 byte. **qmail-popup** then waits for *subprogram* to finish. It prints an error message if *subprogram* crashes or exits nonzero.

**qmail-popup** should be used only within a secure network. Otherwise an eavesdropper can steal passwords. Even if you use APOP, an active attacker can still take over the connection and wreak havoc.

**qmail-popup** has a 20-minute idle timeout.

**qmail-popup** is based on a program contributed by Russ Nelson.

## SEE ALSO

[maildir(5)](/maildir/5.md), [qmail-local(8)](/qmail-local/8.md), [qmail-pop3d(8)](/qmail-pop3d/8.md)