HP TCP/IP Services for OpenVMS
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19.1.6.1.1 SMTP Address

The POP server uses the SMTP address within the quotation marks to rebuild the From: field of an SMTP address. For example, message header From: SMTP%"james.jones@federation.gov" becomes:


From: james.jones@federation.gov 

SMTP hides nested quotation marks by changing them to cent sign (¢) characters before passing them to OpenVMS Mail and then changing them back after a reply. The POP server removes any cent signs that designate double quotation marks. For example, the following message header:


From: SMTP%"¢ABCMTS::MRGATE::\¢ABCDEF::VIVALDI \¢¢@xyz.org" 

Becomes:


From: "ABCMTS::MRGATE::\"ABCDEF::VIVALDI\""@xyz.org" 

19.1.6.1.2 DECnet Address

The TCPIP$POP_DECNET_REWRITE logical name values define how the POP server rebuilds a DECnet address, as shown in the following list:

19.1.6.1.3 User Name-Only Address

If an SMTP substitute domain is defined, the POP server appends it to the user name, followed by a commercial at sign (@). Otherwise, POP uses the local host name.

For example, with a substitute domain defined as acme.widgets.com , the message header From: Smith becomes:


From: smith@acme.widgets.com 

19.1.6.1.4 DECnet Address That Contains Quotation Marks

The values assigned to the TCPIP$POP_QUOTED_DECNET_REWRITE logical name define how the POP server rebuilds a DECnet address that contains quotation marks. The values are:

19.1.6.1.5 Cluster-Forwarding SMTP Address

With a cluster-forwarding SMTP address, the POP server uses the SMTP address within the quotation marks. For example, the message header From: ABCDEF::SMTP%"james.jones@federation.gov" becomes:


From: james.jones@federation.gov 

19.1.6.1.6 All Other Addresses

For all other address formats, the POP server changes the entire address to the SMTP format:

For example, if the substitute domain is xyz.org , the message header From: ABCMTS::MRGATE::"ORDERS::SPECIAL" becomes:


From: "ABCMTS::MRGATE::\"ORDERS::SPECIAL\""@xyz.org 

If the logical name TCPIP$POP_IGNORE_MAIL11_HEADERS is defined and the address is an SMTP address, the rebuilt From: field is not displayed to the user. In this case, the POP server sends the actual headers from the body of the mail as the mail headers.

19.2 POP Server Startup and Shutdown

The POP server process starts automatically if you specified automatic startup during the configuration procedure (TCPIP$CONFIG.COM).

The POP server can be shut down and started independently of TCP/IP Services. This is useful when you change parameters or logical names that require the service to be restarted.

The following files are provided:

To preserve site-specific parameter settings and commands, create the following files. These files are not overwritten when you reinstall TCP/IP Services:

19.3 Modifying POP Server Characteristics

To modify the default POP server settings and configure additional characteristics, define TCPIP$POP logical names in the POP_SYSTARTUP.COM file. If you modify the POP startup file, restart the POP server to make the changes take effect.

You can modify the following POP server characteristics:

Table 19-2 outlines the POP logical names, default settings, and characteristic options.

Table 19-2 POP Logical Names
Logical Name Description
TCPIP$POP_SECURITY value Defines a level of security for the POP server. Determines the timing and text of error messages sent from the POP server to the POP client when authorization errors occur (for example, when an invalid user name or password is sent):
  • FRIENDLY (default)

    The error messages provide information about a particular error. For example, if a password is incorrect, the client receives the following error message:

    -ERR password supplied for "jones" is incorrect
    
  • SECURE

    One error message is sent in response to all authorization errors except when an invalid user name is specified. For example:

    Access to user account "jones" denied
    

    When the POP server receives an invalid user name, it replies to the POP client with a +OK message. After the POP client sends the password, the POP server sends the -ERR access denied message. This method prevents an unauthorized user from knowing whether the access was denied because of an incorrect user name or password.

TCPIP$POP_DISABLE_CLEARTEXT If defined, the POP server process does not serve incoming connections to the cleartext POP port (port 110). It will listen on port 110 and respond to any client that tries to connect with a failure message. See Section 19.5.3 for more information.
TCPIP$POP_DISABLE_SSL If defined, the POP server process does not serve incoming connections to the Secure POP port (port 995). The POP server does not listen on port 995. Clients trying to connect have their connections rejected. See Section 19.5.3 for more information.
TCPIP$POP_CERT_FILE Specifies the name of the certificate file that POP uses for SSL. If not defined, the default is SSL$CERTS:SERVER.CRT. See Section 19.5.3 for more information.
TCPIP$POP_KEY_FILE Specifies the name of the key file that POP uses for SSL. If not defined, the default is SSL$KEY:SERVER.KEY. See Section 19.5.3 for more information.
TCPIP$POP_TRACE If defined, the POP server records all messages sent to and received from the POP client in a log file.
TCPIP$POP_LOG_LEVEL value Defines the type of messages logged by the POP server:
  • ERROR

    Logs only error messages.

  • INFORMATIONAL (default)

    Logs informational messages and error messages.

  • THREAD

    Logs information about client and server interactions as well as informational and error messages.

  • DEBUG

    Logs full diagnostic information. This is used for problem diagnosis.

TCPIP$POP_POSTMASTER value Defines a person or persons to receive a failure mail message from the POP server startup procedure (TCPIP$POP_STARTUP.COM) when the POP server exits with an error. For example, to have the failure mail message sent to users JONES and SMITH, define the logical name as follows:
$ DEFINE/SYSTEM TCPIP$POP_POSTMASTER "JONES, SMITH"

TCPIP$POP_MESSAGE_MAXIMUM n Defines the maximum number of mail messages that a single client can download per connection, where n is a number from 0 to 65,535. If not defined, the POP server uses the default value of 0 (no maximum).
TCPIP$POP_LINK_IDLE_TIMEOUT n Determines the length of time the server allows a link to a POP client to remain idle, where n is a number specified in OpenVMS delta time delimited by quotation marks. A POP link remains active until it is released by the POP client.

If not defined, the POP server does not set a link idle value (0 00:00:00.00).

TCPIP$POP_PERSONAL_NAME If defined, the POP server provides the POP clients with the message header From: fields that include the sender's personal name, if one appeared in the sender's From: field.
TCPIP$POP_LEAVE_IN_NEWMAIL If defined, mail that has been read by the PC client but not deleted remains in the NEWMAIL folder. Allows users to access mail from different systems and determine when to move or delete the mail from the POP server. If not defined, mail that has been read but not deleted is moved to the MAIL folder.
TCPIP$POP_USE_MAIL_FOLDER If defined, moves all mail to the MAIL folder and displays this folder instead of the NEWMAIL folder.
TCPIP$POP_FAST_SCAN If defined, the POP server estimates the number of bytes for the size of the mail message based on the number of lines in the message instead of counting the exact number of bytes. Setting this logical may improve performance.
TCPIP$POP_MAXIMUM_THREADS Allows you to define the number of process threads that POP can activate. The default is 15. If you set this logical to 1, the POP server becomes single threaded. This logical is recommended only as a temporary solution to system resource problems.
TCPIP$POP_IGNORE_MAIL11_HEADERS If defined, the POP server ignores the OpenVMS message headers when the OpenVMS Mail From: field contains an SMTP address, which indicates that the message has come from SMTP.

For information about how POP forms message headers, see Section 19.1.6.

TCPIP$POP_SEND_ID_HEADERS If defined, the POP server sends X-POP3-Server and X-POP3-ID headers for each mail message. If not defined, the ID headers are not sent for any mail from an SMTP address. For information about how POP handles message headers, see Section 19.1.6.
TCPIP$POP_DECNET_REWRITE value Determines how the POP server rebuilds a simple DECnet address (of the form node::user) in the OpenVMS Mail From: field when it sends the mail to the POP client; value is one of the following:
  • GENERIC

    Simple DECnet addresses are changed to the SMTP address format.

  • NONE

    Simple DECnet addresses are sent unmodified to the POP client.

  • TRANSFORM (default)

    The POP server attempts to transform the DECnet address into an SMTP address by translating the DECnet node name to a TCP/IP host name.

For more information about how POP rebuilds the message headers, see Section 19.1.6.1.2.

TCPIP$POP_QUOTED_DECNET_REWRITE
value
Determines how the POP server rebuilds a DECnet address that contains quotation marks (an address of the form node::"user@host") in the OpenVMS Mail From: field when it sends the message to the POP client; value is one of the following:
  • GENERIC

    DECnet addresses that contain quotation marks are changed to the SMTP address format.

  • NONE

    DECnet addresses that contain quotation marks are sent unmodified to the POP client.

  • TRANSFORM (default)

    The POP server uses the text within the quotation marks in the From: field it sends to the POP server.

For more information about how POP rebuilds the message headers, see Section 19.1.6.1.4.

TCPIP$POP_SNDBUF n Allows you to increase or decrease the size of the TCP flow control buffer. Sets the SO_SNDBUF socket option to a specific number; n is the number 512 or greater. If not defined, the POP server uses the value specified in the SHOW PROTOCOL/PARAMETERS command.
TCPIP$POP_DISUSERPASS Disables the client USER and PASS commands and sends a failure message to the POP client on receipt of either command. For more information about POP user authorization methods, see Section 19.1.5.
TCPIP$POP_PURGE_RECLAIM If defined, the POP server performs a PURGE/RECLAIM command action after it deletes messages.

19.4 Enabling MIME Mail

The MIME (Multipurpose Internet Mail Extensions) specification provides a set of additional headers you can use so users can send mail messages composed of more than simple ASCII text. MIME is an enhancement to RFC 822.

For MIME mail to be decoded correctly, follow these guidelines:

If MIME mail does not decode, check the mail headers on the client system. If you see multiple blocks of headers and the MIME version header is not in the first block, confirm that you have followed these guidelines.

19.5 Secure POP

Secure POP provides secure retrieval of mail.

The secure POP server accepts connections on port 995. Secure POP encrypts passwords, data, and POP commands and is compatible with clients that use the Secure Sockets Layer (SSL), such as Microsoft Outlook.

To use this feature, you must download the HP SSL kit for OpenVMS Alpha from the HP OpenVMS web site. If the OpenVMS SSL software is not installed, the POP server will communicate in non-SSL mode. It is easy to configure the SSL POP server. You can use self-signed certificates or CA-issued certificates for greater security. For more information, see the HP Open Source Security for OpenVMS manual.

The POP client must also be configured to use the secure POP server. Refer to your client documentation for procedures.

19.5.1 Installing SSL Shareable Images

The POP server image is installed with privileges, requiring that the shareable images that it loads be installed. Therefore, the following images must be installed before the POP server:


$ INSTALL CREATE SYS$LIBRARY:SSL$LIBCRYPTO_SHR32.EXE 
 
$ INSTALL CREATE SYS$LIBRARY:SSL$LIBSSL_SHR.EXE 

The secure POP startup procedure does not install these images. You must ensure they are installed before the TCP/IP Services startup procedure runs.

The POP server is implemented with links to the OpenVMS SSL software, thereby allowing new versions of the SSL software to be installed and utilized by the POP server automatically. The SSL software must be loaded with the OpenVMS INSTALL command for any changes to affect the POP server.

19.5.2 Starting SSL before TCP/IP Services

The SSL logical names are defined by the SSL startup procedure. Therefore, if you have POP configured to use SSL logical names to locate the certificate and key files, you must ensure that the SSL startup procedure is run before the TCP/IP Services startup procedure.

19.5.3 Controlling Secure POP With Logical Names

You can use the following logical names to control the way the POP server works:


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