Change POP Server Attributes (CHGPOPA)

The Change POP Mail Server Attributes (CHGPOPA) command is used to change the Post Office Protocol (POP) Version 3 Mail Server attributes. The changes take effect the next time the POP3 server is started either by the Start TCP/IP (STRTCP) command or by the Start TCP/IP Server (STRTCPSVR) command.



Keyword Description Choices Notes
AUTOSTART Autostart servers *YES, *NO, *SAME Optional, Positional 1
NBRSVR Number of initial servers 1-20, *SAME, *DFT Optional
INACTTIMO Inactivity timeout 10-65535, *SAME, *DFT Optional
MSGSPLIT Message split size 32-2048, *SAME, *DFT, *NOMAX Optional
MIMECCSID MIME CCSID Element list Optional
Element 1: Coded character set identifier *SAME, *DFT, 819, 912, 915, 1089, 813, 916, 920, 5052, 367, 923
Element 2: When to use *SAME, *BESTFIT, *ALWAYS
ALWSSL Allow secure sockets layer *SAME, *YES, *NO, *ONLY Optional
BNDADR POP3 server bind addresses Single values: *SAME, *ANY
Other values (up to 25 repetitions): Character value

Autostart servers (AUTOSTART)

Specifies whether to automatically start the POP mail server when TCP/IP is started by running the Start TCP/IP (STRTCP) command, or the Start TCP/IP Server (STRTCPSVR) command with SERVER(*AUTOSTART) specified. When the POP mail server is started by running the STRTCPSVR command, and SERVER(*AUTOSTART) is not specified, this parameter is ignored and the POP mail server is started regardless of the value of this parameter. If STRTCPSVR *POP is specified, and the POP server is already running, then an additional server job is started.

The AUTOSTART value does not change if it was previously set. Otherwise, *NO is used.
Do not automatically start any POP mail server jobs. If you do not intend to use the POP mail server, set AUTOSTART to *NO.
Start the number of server jobs specified for the Number of initial servers (NBRSVR) parameter.

Number of initial servers (NBRSVR)

Specifies the number of POP mail server jobs to start when POP is started by either the Start TCP/IP (STRTCP) command or the Start TCP/IP Server (STRTCPSVR) command. These jobs allow new clients to connect to the server without having to wait for the overhead associated with starting a new job. The server tries to keep at least this number of jobs available for connecting to new clients as the number of connected clients changes. This is a performance enhancement for the POP mail server that reduces the system overhead each time a client connects.

The number of server jobs does not change if it was previously set; otherwise 3 is used.
The number of server jobs is set to the default value of 3.
Specify the number of server jobs to start.

Inactivity timeout (INACTTIMO)

Specifies the number of seconds of inactivity between the client and server before the server assumes the client has stopped communicating and disconnects from the client. When this event occurs the server does not delete any mail in the user's mail box to ensure that mail is not lost.

The inactivity timeout value does not change if it was previously set; otherwise 600 seconds (10 minutes) is used.
The inactivity timeout value is set to the default value of 600 seconds (10 minutes).
Specify the number of seconds to use for the inactivity timeout value.

Message split size (MSGSPLIT)

Specifies the number of kilobytes that will be used for partial message blocks when the mail message exceeds this count. This is used only for remote mail delivery. This is a network parameter and is determined by the capacities of the network gateways you are connected to. Changes to this parameter take effect immediately; you do not need to restart the POP server. This parameter is only used if the DIRTYPE parameter on the CHGSMTPA command is set to *SDD.

The value does not change if it was previously set; otherwise *NOMAX is used.
Disables message splitting, data is sent as one message.
The message split size is set to the default value of *NOMAX.
Specify the number of kilobytes to use for the message split size.


Specifies the MIME coded-character set identifier (CCSID) conversion parameters for text data. You must restart the mail server framework (using the STRMSF command) for changes to this parameter to take effect.

Element 1: Coded character set identifier

CCSID value to be used for single-byte character set (SBCS) and some mixed-byte character set (MBCS) ASCII translations when doing ASCII-to-EBCDIC and EBCDIC-to-ASCII mapping.

The CCSID value that was previously set does not change. Otherwise, 00819 (ISO 8859-1 8-bit ASCII) is used.
Specify an ASCII CCSID value from the following list. This value is validated to ensure that you are specifying a valid MIME Standard ASCII CCSID.

MIME Standard:  US-ASCII
Name:  US English


MIME Standard:  ISO-8859-1
Name:  Latin-1


MIME Standard:  ISO-8859-2
Name:  Latin-2


MIME Standard:  ISO-8859-5
Name:  Cyrillic


MIME Standard:  ISO-8859-6
Name:  Arabic


MIME Standard:  ISO-8859-7
Name:  Greek


MIME Standard:  ISO-8859-8
Name:  Hebrew


MIME Standard:  ISO-8859-9
Name:  Latin-5


MIME Standard:  ISO-8859-15
Name:  Latin-9
EBCDIC CCSIDs:  01140-1149


MIME Standard:  ISO-2022-JP
Name:  Japan MBCS

Element 2: When to use

Specifies whether or not to force conversion of mail to or from the ASCII CCSID specified on the CCSID parameter. This configured parameter is a global parameter; once you set it to *ALWAYS, it dictates the CCSID that all EBCDIC-to-ASCII mail will use. This parameter should only be set to *ALWAYS if there is a requirement to limit the character set. This should be communicated to all clients requiring mail interchange, particularly where language differences could cause a loss of certain language-specific symbols.

The attribute does not change if it was previously set; otherwise *BESTFIT is used.
Use the specified CCSID only if the Mail Server Framework is unable to determine the CCSID from the data in the mail.
Always use the specified CCSID, even if the Mail Server Framework would have used a best-fit CCSID. For incoming mail, the specified CCSID is used if the MIME character set is not supported by the Mail Server Framework. For outgoing mail, EBCDIC-to-ASCII will always convert to the specified CCSID.

Allow secure sockets layer (ALWSSL)

Specifies whether the POP server should use encryption to secure POP datastreams (including passwords). Encryption is provided with either the Secure Sockets Layer (SSL) or the Transport Layer Security (TLS). The selection of TLS or SSL is determined by the outcome of the security negotiation between the POP client and server.

The allow TLS/SSL value that was previously set does not change; otherwise, *YES is used.
The POP server accepts non-secure POP sessions. If a valid POP server certificate is configured in the Digital Certificate Manager, TLS/SSL sessions will also be allowed.
The POP server will only accept non-secure POP sessions.
The POP server allows login only from TLS/SSL POP sessions.

Note:If ALWSSL(*ONLY) is specified and a valid POP server certificate is not configured in the Digital Certificate Manager, the POP server will not start.

POP3 server bind addresses (BNDADR)

Specifies the list of TCP/IP interfaces that the POP3 server will listen on at server startup. Duplicate TCP/IP interfaces are not allowed. If there is an error on binding to an interface on startup that interface will be skipped. The server will start if and only if there is at least one interface that can successfully bind.

Single values

The TCP/IP binding interfaces that were previously set do not change; otherwise, *ANY is used.
The POP3 Server will bind to any TCP/IP interface available.

Other value (up to 25 repetitions)

Specify the internet address of the TCP/IP interface for the POP3 server to listen on.


Example 1: Setting an Inactivity Timeout


This command sets the time of 700 seconds that the POP server will wait before assuming the client has stopped communicating. After this time the server will disconnect from the client. No mail will be deleted.

Example 2: Setting a Default CCSID


This command sets the CCSID 923 to be used for conversions, if the CCSID cannot be determined from the mail. This CCSID contains the Euro character.

Example 3: Setting an Allow Secure Socket Layer


This command sets the POP server to use only secure communication between the client and server.

Error messages

*ESCAPE Messages

Error accessing configuration member.
CCSID parameter value &1 not valid.
CCSID parameter value &1 not found.
*IOSYSCFG authority required to use &1.
File &3 in library &2 not available.