To check the email in an account's inbox using Post Office Protocol version 3 (POP3) commands from a command-line interface (CLI), if the POP3 server, e.g., Dovecot, is listening on the default well-known port of 110 by connecting to the POP3 server using Telnet and issuing the following commands:
Authentication
- user <username> - enter the username for the account
- pass <password> - enter the password for the account
Mailbox Status & Information
- stat - see the number of messages in the inbox
- list [msg] - lists all messages or a specific message number along with its size
- uidl [msg] <n> - returns the unique message ID for tracking a specific email
- capa - request a list of the server's capabilities
Mail Retrieval
- retr <msg> – the retrieve command downloads/displays the full content of the specified message number
- top <msg> <n> – retrieves the message header plus a specified number (n) of body lines.
Mail Management & Session Control
- dele <msg> - delete a particular message
- rset - Unmarks any messages that were previously marked for deletion during the session
- noop - performs no operation (can be used as a keep-alive check)
- quit - disconnect from the POP3 server
E.g.:
# telnet 127.0.0.1 110 Trying 127.0.0.1... Connected to 127.0.0.1. Escape character is '^]'. +OK Dovecot ready. capa +OK CAPA TOP UIDL RESP-CODES PIPELINING AUTH-RESP-CODE STLS USER SASL PLAIN . user nell +OK pass thePassword +OK Logged in. stat +OK 278 59431689 retr 278 +OK 691 octets Return-Path: <jdoe@moonpoint.com> Received: from moonpoint.com (localhost [127.0.0.1]) by moonpoint.com (8.14.7/8.14.7) with ESMTP id 6A4122DY022073 for <nell@moonpoint.com>; Tue, 3 Nov 2026 20:02:02 -0500 Received: (from jdoe@localhost) by moonpoint.com (8.14.7/8.14.7/Submit) id 6A4122iG022070 for nell@moonpoint.com; Tue, 3 Nov 2026 20:02:02 -0500 Date: Tue, 3 Nov 2026 20:02:02 -0500 From: jdoe <jdoe@moonpoint.com> To: nell@moonpoint.com Subject: Example email Message-ID: <20261104010202.GA21379@moonpoint.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.5.21 (2010-09-15) This is an example email. . dele 278 +OK Marked to be deleted. rset +OK noop +OK quit +OK Logging out, messages deleted. Connection closed by foreign host. #
Or, if you want to see the size of a particular message, its unique message ID, or just a portion of the message rather than the entire message:
[jdoe@moonpoint ~]$ telnet 127.0.0.1 110 Trying 127.0.0.1... Connected to 127.0.0.1. Escape character is '^]'. +OK Dovecot ready. user nell +OK pass thePassword +OK Logged in. stat +OK 292 60503043 list 292 +OK 292 713 uidl 292 +OK 292 00026d86481e759f top 292 +OK Return-Path: <abigail@moonpoint.com> Received: from moonpoint.com (localhost [127.0.0.1]) by moonpoint.com (8.14.7/8.14.7) with ESMTP id 6A60FcqT005571 for <nell@moonpoint.com>; Thu, 5 Nov 2026 19:15:38 -0500 Received: (from abigail@localhost) by moonpoint.com (8.14.7/8.14.7/Submit) id 6A60FcLW005570 for nell@moonpoint.com; Thu, 5 Nov 2026 19:15:38 -0500 Date: Thu, 5 Nov 2026 19:15:38 -0500 From: Abigail Adams <abigail@moonpoint.com> To: nell@moonpoint.com Subject: Test email Message-ID: <20261106001538.GA5472@moonpoint.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.5.21 (2010-09-15) . top 292 5 +OK Return-Path: <abigail@moonpoint.com> Received: from moonpoint.com (localhost [127.0.0.1]) by moonpoint.com (8.14.7/8.14.7) with ESMTP id 6A60FcqT005571 for <nell@moonpoint.com>; Thu, 5 Nov 2026 19:15:38 -0500 Received: (from abigail@localhost) by moonpoint.com (8.14.7/8.14.7/Submit) id 6A60FcLW005570 for nell@moonpoint.com; Thu, 5 Nov 2026 19:15:38 -0500 Date: Thu, 5 Nov 2026 19:15:38 -0500 From: Abigail Adams <abigail@moonpoint.com> To: nell@moonpoint.com Subject: Test email Message-ID: <20261106001538.GA5472@moonpoint.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.5.21 (2010-09-15) A test message. Abigail . dele 292 +OK Marked to be deleted. quit +OK Logging out, messages deleted. Connection closed by foreign host. [jdoe@moonpoint ~]$
