POP3 on the command line

You sometimes find the need to run a protocol dialogue on the command line via telnet. I recently had to do this for POP3. In fact it’s quite simple if you follow the example below where lines starting with a plus are responses from the server:

telnet my.pop.server 110
Trying 123.456.789.123...
Connected to my.pop.server.
Escape character is '^]'.
+OK Hello there.
user user@my.pop.server
+OK Password required.
pass secret
+OK logged in.
list
+OK POP3 clients that break here, they violate STD53.
1 2213
2 2823
.
retr 1
+OK 2213 octets follow.
[email content]
.
dele 1
+OK Deleted.
quit
+OK Bye-bye.

The answer of the server could have a slightly different text which differs from server to server. However the dialogue is still the same.

The most common command shows the list below

command	explanation
quit	terminates the session and deletes messages marked for deletion
stat	statistics about total count and size of mails
list	list of mail and their size
retr no.	retrieve the content of mail with number no.
dele no.	mark mail no. for deletion
noop	no operation, returns an OK (useful to keep the connection up)
rset	resets all changes and marks
top no. lines	show the first lines of message number no.
user name	authenticate as user name
pass password	submit password for current user
uidl	show unique ID of each mail (this is used by your POP3 client if you like to keep the mail on the server)