---
name: "pop2d"
section: "8"
platform: "linux"
package: "netstd"
version: "2.08-1"
release: "Debian 1.2 (Rex)"
platforms: ["linux"]
url: "https://new.carta.tech/pop2d"
---

# pop2d(8)

remote maildrop access server

## NAME

**pop2d** - remote maildrop access server

## SYNOPSIS

**/usr/sbin/in.pop2d**

## DESCRIPTION

**Pop2d** is a mailbox server based on the Internet RFC937, Post Office Protocol Version 2. The program allows remote access to UNIX maildrops found in **/var/spool/mail**. The server requires user and password verification before a maildrop can be opened. The server can retrieve and delete messages from the maildrop on a per-message basis.

**Pop2d** listens for TCP requests on port 109. Once connected it expects single line commands terminated by a \<CR-LF\>.

**Pop2d** currently supports the following POP2 commands; the commands are case independent. In addition, the server supports one extension command, HOST, which allows access to BSMTP formatted maildrops in the directory **/var/spool/pop**.

The syntax for the HOST command is:   HOST \<hostname\>

Example:	HOST fennario.ucdavis.edu

this will open the file at /var/spool/pop/fennario.ucdavis.edu

Command	Description\
 HELO		specify maildrop user and password\
 FOLD		open a UNIX maildrop (FromSPACE delimited)\
 HOST		open a BSMTP maildrop in **/var/spool/pop**\
 READ		switch to a message in a maildrop\
 RETR		retrieve a message in a maildrop\
 ACKS		save message just retrieved, switch to next\
 ACKD		delete message just retrieved, switch to next\
 NACK		save message just retrieved, prepare to resend\
 QUIT		terminate session

## FILES

/var/spool/mail/\*	UNIX FromSPACE delimited maildrops /var/spool/pop/\*	BSMTP formatted maildrops

## SEE ALSO

[pop2d(8)](/pop2d/8.md)

## AUTHOR

Katie Stevens, dkstevens@ucdavis.edu\
 Information Technology -- Campus Access Point\
 University of California, Davis

## NOTES

The POP2 standard has been superseded by Post Office Protocol Version 3 (POP3), described in RFC1081.