Technical data

The POP server uses security features provided in the protocol and in the
OpenVMS operating system, as well as additional security measures. These
methods provide a secure process that minimizes the possibility of inappropriate
access to a user’s mail file on the served system.
You can modify the POP server default characteristics, and you can implement
new characteristics by defining logical names described in the Compaq TCP/IP
Services for OpenVMS Management guide.
6.1.2 How to Access Mail Messages from the POP Server
To access mail messages from the POP server, you configure a user name and
password or the POP shared secret-password string, into your client mail
application.
Your client system opens the TCP connection and attempts to access the server
by entering applicable POP commands such as USER (user name) and PASS
(password), or APOP (shared secret password). In addition, POP supports the UID
command, which some POP clients use, in which the UID (user identification)
that POP creates for each mail message is a concatenation of the user name and
thedateofarrival.
By default, the POP server reads mail from the user’s OpenVMS NEWMAIL folder.
If you do not instruct the POP server to delete the mail, the server either moves the
mail to the MAIL folder (if the logical name TCPIP$POP_USE_MAIL_FOLDER
is defined) or keeps it in the NEWMAIL folder (if the logical name
TCPIP$POP_LEAVE_IN_NEWMAIL is defined). These logical names are
described in the Compaq TCP/IP Services for OpenVMS Management guide.
6.1.3 How the POP Server Handles Foreign Message Formats
POP contains minimal support for mail messages that contain foreign formats.
Such messages are usually binary and therefore are not transferred to the POP
client. Instead, the POP server transfers the message headers, along with a brief
message instructing the user to log in and extract the foreign message into a file.
Foreign messages are moved into your OpenVMS MAIL folder; the POP server
then never deletes.
6.1.4 How the POP Server Authorizes Users
Table 6–1 describes the methods the POP server process uses to authorize user
access.
6–2 Mail Services