HP OpenVMS Systems Documentation
Compaq TCP/IP Services for OpenVMS
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:
The values assigned to the TCPIP$POP_QUOTED_DECNET_REWRITE logical name define how the POP server rebuilds a DECnet address that contains quotation marks. The values are:
With a cluster-forwarding SMTP address, the POP server uses the SMTP address within the quotation marks. For example, the message header From: ABCDEF::SMTP%"email@example.com" becomes:
For all other address formats, the POP server changes the entire address to the SMTP format:
For example, if the substitute domain is xyz.org , the message header From: ABCMTS::MRGATE::"ORDERS::SPECIAL" becomes:
If the logical name TCPIP$POP_IGNORE_MAIL11_HEADERS is defined and the
address is an SMTP address, the rebuilt
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.
18.2 POP Server Startup and Shutdown
The POP server process starts automatically if you specified automatic startup during the configuration procedure (TCPIP$CONFIG.COM).
The POP server can be shut down and started independently of TCP/IP Services. This is useful when you change parameters or logical names that require the service to be restarted.
The following files are provided:
To preserve site-specific parameter settings and commands, create the following files. These files are not overwritten when you reinstall TCP/IP Services:
To modify the default POP server settings and configure additional characteristics, define TCPIP$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 18-2 outlines the POP logical names, default settings, and characteristic options.
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):
|TCPIP$POP_TRACE||If defined, the POP server records all messages sent to and received from the POP client in a log file.|
Defines the type of messages logged by the POP server:
Defines a person or persons to receive a failure mail message from the
POP server startup procedure (TCPIP$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
$ 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).|
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
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 mail is sent from SMTP, which contains an SMTP address in the From: field. For information about how POP forms message headers, see Section 18.1.6.|
|TCPIP$POP_SEND_ID_HEADERS||If defined, the POP server sends X-POP3-Server and X-POP3-ID headers for each mail message. If not defined, the ID headers are not sent for any mail from an SMTP address. For information about how POP handles message headers, see Section 18.1.6.|
Determines how the POP server rebuilds a simple DECnet address (of the
node::user) in the OpenVMS message
field when it sends the mail to the POP client;
value is one of the following:
For more information about how POP rebuilds the message headers, see Section 184.108.40.206.2.
Determines how the POP server rebuilds a DECnet address that contains
quotation marks (an address of the form
node::"user@host") in the OpenVMS Mail
field when it sends the message to the POP client;
value is one of the following:
For more information about how POP rebuilds the message headers, see Section 220.127.116.11.4.
|TCPIP$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$POP_DISUSERPASS||Disables the client USER and PASS commands and sends a failure message to the POP client on receipt of either command. For more information about POP user authorization methods, see Section 18.1.5.|
|TCPIP$POP_PURGE_RECLAIM||If defined, the POP server performs a PURGE/RECLAIM command action after it deletes messages.|
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:
$ DEFINE/SYSTEM TCPIP$SMTP_JACKET_LOCAL 1
If MIME mail does not decode, check the mail headers on the client
system. If you see multiple blocks of headers and the MIME version
header is not in the first block, confirm that you have followed these
18.5 Solving POP Problems
The following sections describe ways to troubleshoot problems associated with using the POP server. Some of these include:
Many of the problems encountered using POP pertain to failed or misinterpreted commands or authorization errors. As the first step toward solving problems, you should review the messages provided by the POP server.
The POP server logs command error and OPCOM (authorization) messages in the file SYS$SYSDEVICE:[TCPIP$POP]POP_RUN.LOG. By default, the POP server sends informative error messages to the client about specific errors.
If the SERVICE database log option REJECT is set, the POP server sends OPCOM messages when it rejects POP client commands because of authorization failures. These errors include the receipt of a client's USER command with an invalid user name, or a PASS command with an invalid password.
By default, OPCOM messages are displayed on the client system and are listed in the log file. To disable OPCOM messages, disable the REJECT logging option for the POP service, as follows:
$ TCPIP SET SERVICE POP/LOG=NOREJECT
For troubleshooting purposes, you can simulate a POP client and enter the XTND commands listed in Table 18-3 to obtain information.
|XTND CLIENT||Logs POP client information (if the client supplies it). Helpful for troubleshooting if you use POP with a variety of POP clients that identify themselves.|
|XTND LOGLEVEL||Dynamically adjusts POP logging level. Supported levels are INFORMATIONAL (default), ERROR, THREAD, and DEBUG.|
Displays POP statistics in the following format:
+OK Statistics follow
|XTND SHUTDOWN||Performs an orderly shutdown of POP. Waits for current client connections to disconnect. Recommended over the DCL command STOP.|
To simulate a POP client and obtain information:
$ TELNET UCXSYS 110 %TELNET-I-TRYING, Trying ... 18.104.22.168 %TELNET-I-SESSION, Session 01, host ucxsys, port 110 +OK POP server TCPIP Version 5.0, OpenVMS V7.1 Alpha at ucxsys.acme.com, up since 1999-04-04 06:42:17 <24A00E61._6_APR_1999_06_02_31_15@ucxsys.acme.com> USER username +OK Password required for "username" PASS password +OK Username/password combination ok XTND LOGLEVEL DEBUG +OK logging level changed to debug QUIT +OK TCPIP POP server at ucxsys.acme.com signing off.