UNIXではCUIでのPOP3受信にtelnetを使えます。
telnet pop3
USER
PASS
STAT
QUIT
それぞれのコマンド(USER,PASS,STAT,QUIT)で'OK'が返ってくればサーバーとのやりとりはまず大丈夫です。
例)
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telnet foo.or.jp pop3
Trying xxx.xxx.xxx.xxx...
Connected to foo.or.jp.
Escape character is '^]'.
+OK QPOP (version 3.0.2) at foo.or.jp starting. <35954.1029563310@foo.or.jp>
USER saitou
+OK Password required for saitou.
PASS xxxxxxx
+OK saitou has 1 visible message (0 hidden) in 5140 octets.
STAT
+OK 1 5140
QUIT
+OK Pop server at tasogare.imasy.or.jp signing off.
Connection closed by foreign host.
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ラベル:パソコン