2.2.6 [RFC1939] Section 5, LIST Command

V0003:

The specification states: "Arguments: a message-number (optional), which, if present, may NOT refer to a message marked as deleted."

Microsoft Office Outlook 2007, Microsoft Outlook 2010, Microsoft Outlook 2013, Microsoft Outlook 2016, Microsoft Outlook 2019

The client MAY send the message-number argument with the LIST command.

Outlook never sends an argument to the LIST command.

C0018:

The specification states: "Restrictions: may only be given in the TRANSACTION state."

Office Outlook 2007, Outlook 2010, Outlook 2013, Outlook 2016, Outlook 2019

The client SHOULD only send the LIST command when in the TRANSACTION state.

C0019:

The specification states: "Discussion: If an argument was given and the POP3 server issues a positive response with a line containing information for that message. This line is called a "scan listing" for that message."

Office Outlook 2007, Outlook 2010, Outlook 2013, Outlook 2016, Outlook 2019

If the LIST command includes an argument and the server returns success, then the server MUST issue a positive response line (a "scan listing"). Outlook does not send an argument with the LIST command, so no server response is issued.

C0020:

The specification states: "If no argument was given and the POP3 server issues a positive response, then the response given is multi-line. After the initial '+OK' for each message in the maildrop, the POP3 server responds with a line containing information for that message."

Office Outlook 2007, Outlook 2010, Outlook 2013, Outlook 2016, Outlook 2019

If the LIST command does not include an argument and the server issues a positive response, then the response given MUST be multi-line. The initial line MUST be the positive response "+OK". Then the server MUST send a "scan list" for each message in the maildrop on its own line.

C0021:

The specification states: "All POP3 servers are required to use a certain format for scan listings. A scan listing consists of the message-number of the message, followed by a single space and the exact size of the message in octets."

Office Outlook 2007, Outlook 2010, Outlook 2013, Outlook 2016, Outlook 2019

The "scan listing" MUST consist of the number of the message followed by one or more space or tab characters and then the exact size of the message in octets. The server MAY follow this with additional information.