gtpc1m55Transmission Control Protocol/Internet Protocol

TPF Internet Mail Server Configuration Files

The behavior of the TPF Internet mail servers is controlled by the following configuration files, which must be located in the basic subsystem (BSS):

You can also create an optional access list configuration file, named /etc/postfix/access. An access list is a file that directs the SMTP server to selectively accept or reject mail from or to specific hosts, domains, networks, host addresses, or mail addresses.

Each configuration file is an EBCDIC file that defines the configuration parameters for that server. Blank lines and lines beginning with a # symbol are ignored. You can create and update the configuration files by doing one of the following:

SMTP Configuration File Parameters

Each line of SMTP configuration file /etc/postfix/main.cf must be in the following format:

smtpparm = value

where smtpparm is the name of the configuration parameter and value is the parameter value that you want to specify. The following describes the configuration parameters for the /etc/postfix/main.cf file.

myhostname = name
Specifies the Internet host name of the TPF Internet mail system, where name is the host name in fully qualified domain name format. You must specify this configuration parameter. $myhostname, which represents the value of the myhostname configuration parameter, is used as the default value in many other configuration parameters.

mydomain = domain
Specifies the local Internet domain name of the TPF Internet mail system, where domain is the local domain name. If you do not specify this parameter, the value for mydomain is derived from the value defined for the myhostname parameter by stripping off the first component. For example, if the value of myhostname is defined as tpf01.tpfmail.com, the default value for mydomain is tpfmail.com. $mydomain, which represents the value of the mydomain configuration parameter, is used as a default value for many other configuration parameters.

mynetworks = ipaddr/mask
Lists all the networks that are attached to the TPF Internet mail system, where

ipaddr
is an Internet Protocol (IP) address of the host in dotted decimal format.

mask
is a number, from 0 to 32, that represents the number of bits in the network part of the host address that are to be compared when checking the address.

For example, if you specify 172.123.255.255/8 for this parameter, any connecting client with an IP address that begins with 172 is considered local and does not require additional restriction testing. However, any connecting client whose IP address does not match 172 is considered to be remote and will continue through additional restriction testing based on other configuration parameter settings. In this example, specifying 172.0.0.0/8 for this parameter has the same effect.

You must specify this parameter. If you specify more than one network, separate each with a comma; for example:

mynetworks = 172.0.0.0/8, 192.255.0.0/16

mail_name = name
Specifies the mail system name that is used in headers of received mail, in the SMTP greeting banner, and in undeliverable (also known as bounced) mail, where name is any character string. If you do not specify this configuration parameter, mail_name is set to Postfix.

smtpd_banner = $myhostname text
A line of text that the TPF Internet mail server sends to the SMTP client, where text is any character string. You must specify $myhostname at the start of the text. If you do not specify this configuration parameter, smtpd_banner is set to $myhostname ESMTP $mail_name. For example, if you specify tpf01.tpfmail.com for the myhostname parameter and TPF Mail for the mail_name parameter, the default smtpd_banner will be:
   tpf01.tpfmail.com ESMTP TPF Mail

maximal_queue_lifetime = numdays
Specifies the maximum amount of time that a mail item can stay in the deferred queue before it is sent back as undeliverable, where numdays is the number of days. If you do not specify this parameter, a value of 5 days is used.

minimal_backoff_time = sec
Specifies the minimum amount of time between delivery attempts of a deferred mail item, where sec is the number of seconds. If you do not specify this parameter, a value of 1000 seconds is used.

ignore_mx_lookup_error = mxerror
Specifies how you want the delivery manager to handle errors from a mail exchange (MX) query, where mxerror is one of the following:

YES
Ignores an MX query error and proceeds to search for an address record.

NO
Does not ignore an MX query error and puts the mail item on the deferred queue.

If you do not specify this parameter, the value is set to NO.

smtpd_helo_required = helomsg
Specifies whether or not the connecting client is required to send a HELO (or EHLO) command at the beginning of a session, where helomsg is either YES or NO. If you do not specify this parameter, the value is set to YES.

smtpd_helo_restrictions = helorstr
Specifies the kind of restrictions that you want to apply when the client sends a HELO command, where helorstr is one or more of the following:

check_helo_acl
Checks the access list file (/etc/postfix/access) for the host name specified by the client and accepts or rejects the request based on the setting in the access list.

permit_mynetworks
Allows the request when the client address matches the value of the mynetworks configuration parameter. If the check passes this restriction, any subsequent checks are ignored.

reject_invalid_hostname
Rejects the request if the syntax of the host name specified by the client is not valid.

Specify zero or more restrictions, separated by commas. Each restriction is applied one at a time, in the order in which you specify them. If you do not specify this configuration parameter, all of these restrictions are enabled in the following order:

smtpd_client_restrictions = clientrstr
Specifies the kind of restrictions you want to apply when the client connects, where clientrstr is one or more of the following:

check_client_acl
Checks the access list file (/etc/postfix/access) for the host name of the client and accepts or rejects the request based on the setting in the access list.

permit_mynetworks
Allows the request when the client address matches the value of the mynetworks configuration parameter. If the check passes this restriction, any subsequent checks are ignored.

reject_unknown_client
Rejects the request if the syntax of the host name of the client is not valid.

Specify zero or more restrictions, separated by commas. Each restriction is applied one at a time, in the order in which you specify them. If you do not specify this configuration parameter, all of these restrictions are enabled in the following order:

smtpd_sender_restrictions = sendrstr
Specifies the kind of restrictions that you want to apply when the client sends a MAIL FROM command, where sendrstr is one or more of the following:

check_sender_acl
Checks the access list file (/etc/postfix/access) for the host name of the sending client and accepts or rejects the request based on the setting in the access list.

reject_unknown_sendom
Rejects the request if the domain portion of the host name of the sending client is not valid.

Specify zero or more restrictions, separated by commas. Each restriction is applied one at a time, in the order in which you specify them. If you do not specify this configuration parameter, all of these restrictions are enabled in the following order:

IMAP/POP Configuration File Parameters

Each line of IMAP/POP configuration file /etc/imapd.conf must be in the following format:

imapparm: value

where imapparm is the name of the configuration parameter and value is the parameter value that you want to specify.

The following lists the configuration parameters for the /etc/imapd.conf file.

Note:
All the parameters for the IMAP/POP configuration file are optional. If you choose to use all the default settings, you must still create the etc/imapd.conf file. The file can be empty or it can contain one or more of the configuration parameters, but it must exist on the BSS; otherwise, the TPF Internet mail servers will not run.

quotawarn: qstor
Specifies the percent of storage that can be used for a mailbox or mailbox hierarchy before the TPF Internet mail server will send a warning message to the client, where qstor is the percent of storage. If you do not specify this configuration parameter, a value of 90 is used. Use the ZMAIL SETQUOTA commandto set the storage limit for a mailbox.

timeout: tmin
Specifies how long the IMAP server will wait before logging off because of inactivity, where tmin is the number of minutes that you want the IMAP server to wait. If you do not specify this parameter, the value is set to 30.

poptimeout: popmin
Specifies how long the POP server will wait before logging off because of inactivity, where popmin is the number of minutes that you want the POP server to wait. If you do not specify this parameter, the value is set to 10.

popminpoll: pollmin
Specifies the minimum amount of time that the server forces users to wait to check mail since the last time mail was checked, where pollmin is the number of minutes you want users to wait. If you do not specify this parameter, the value is set to 0.

autocreatequota: astor
Specifies the quota value (that is, storage limit) for a user mailbox when it is first created, where astor is the maximum number of 4-K records that the mailbox can use. If you do not specify this parameter, the value is set to 256. A quota value of 0 indicates that there is no storage limit. You can change this quota value by using the ZMAIL SETQUOTA command. See TPF Operations for more information about the ZMAIL SETQUOTA command.

TPF Configuration File Parameters

Each line of TPF configuration file /etc/tpf_mail.conf must be in the following format:

tpfparm: value

where tpfparm is the name of the configuration parameter and value is the parameter value that you want to specify.

The following lists the configuration parameters for the /etc/tpf_mail.conf file.

MAIL_SSID: ss
Specifies the name of the TPF subsystem in which you want the TPF Internet mail servers to run, where ss is the subsystem name. You must specify this configuration parameter.

MAX_LOCAL_DELIVERY_MANAGERS: maxlocal
Specifies the maximum number of concurrent entry control blocks (ECBs) that can deliver mail to the local mailboxes, where maxlocal is a decimal number. You must specify this parameter. If you do not specify this parameter, the value is set to 0, which means no mail will be delivered.

MAX_REMOTE_DELIVERY_MANAGERS: maxremote
Specifies the maximum number of concurrent ECBs that can deliver mail to remote mail domains, where maxremote is a decimal number. You must specify this parameter. If you do not specify this parameter, the value is set to 0, which means no mail will be delivered.

MAX_DEFERRED_DELIVERY_MANAGERS: maxdefer
Specifies the maximum number of concurrent ECBs that can process items on the deferred mail queue, where maxdefer is a decimal number. You must specify this parameter. If you do not specify this parameter, the value is set to 0, which means no mail will be delivered.

MAX_HANGING_RECEIVE_MANAGERS: maxrcvmgr
Specifies the maximum number of concurrent ECBs that can accept mail, where maxrcvmgr is a decimal number. You can use this parameter to help improve performance. For example, if you specify a value of 50, the TPF Internet mail server will start 50 permanent mail ECBs to accept mail items and put them on the delivery queue. These ECBs will remain active unless you stop the mail server. This parameter is optional; if you do not specify this parameter, the value is set to 0. There is no maximum value, and the TPF system does not validate the number you specify.
Note:
Each ECB requires about 40 frames; therefore, if you specify too many, the TPF system can enter input list shutdown.

AQ_ACK_TIMER_INTERVAL: aqacksec
Specifies the maximum amount of time for the TPF system to acknowledge the receipt of mail items from a remote client, where aqacksec is the number of seconds. You must specify this parameter; the minimum value is 1.

DQ_ACK_TIMER_INTERVAL: dqacksec
Specifies how often the TPF system will process mail items on the deferred mail queue, where dqacksec is the number of seconds. You must specify this parameter; the minimum value is 1.

DEFER_Q_BACKOFF: qbackoffsec
Specifies the minimum amount of time that the server will wait before attempting to deliver mail from the deferred queue after a previous attempt that failed, where qbackoffsec is the number of seconds. For example, assume this parameter is set to 1800 seconds. If an attempt to deliver mail failed, the server will wait at least 1800 seconds (or 30 minutes) before attempting to deliver that mail item again. You must specify this parameter; the minimum value is 0.

MAIL_DOMAINxx: prime domain ipaddr
Specifies the following:

xx
The fixed file record type associated with this domain. For example, if you define the #MAIL01 fixed file record type, specify this configuration parameter as MAIL_DOMAIN01.

prime
A large prime number to help distribute user accounts evenly across the database. Specify the number 249999991.

domain
The mail domain.

ipaddr
One or more Internet Protocol (IP) addresses for this domain in dotted decimal format. You can specify as many as 256 IP addresses. You must specify a unique value for each domain.

You can use the information in the TPF Internet mail server summary report that is generated from data collection and data reduction to tune some of the values in the TPF configuration file, such as the number of delivery managers. See TPF System Performance and Measurement Reference for more information about the TPF Internet mail server summary report.

Access List Configuration Parameters

Each line of access list configuration file /etc/postfix/access must be in the following format:

pattern action

When pattern matches a mail address, domain, or host address, the SMTP server performs the corresponding action.

Specify pattern in one of the following ways:

user@domain
Matches a specific mail address.

domain.name
Matches the domain name itself and any subdomains of that domain, either in host names or in mail addresses. Top-level domains (such as domains that end in .com or .org) will never be matched.

user@
Matches all mail addresses with the specified user part.

net.work.addr.ess
Matches any host address in the specified network. A network address is a sequence of one or more octets separated by a period (.). You can specify all or part of a network address; for example:

Specify one of the following for action:

ACCEPT
Accepts mail from the address that matches the specified pattern.

REJECT
Rejects mail from the address that matches the specified pattern.

DUNNO
Continues checking other restrictions specified for this area. See the smtpd_helo_restictions, smtpd_client_restrictions and smtpd_sender_restrictions parameters in the SMTP configuration file (/etc/postfix/mail.cf) for more information about other restrictions.