gtpc1m55 | Transmission Control Protocol/Internet Protocol |
The behavior of the TPF Internet mail servers is controlled by the
following configuration files, which must be located in the basic
subsystem (BSS):
- /etc/postfix/main.cf, which specifies the configuration
parameters for the SMTP server
- /etc/imapd.conf, which specifies the configuration
parameters for the IMAP and POP servers
- /etc/tpf_mail.conf, which specifies the configuration
parameters for TPF-unique information.
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:
- Use the ZFILE commands to create and update the files directly on your TPF
system.
- Create and update the files on another system and use Trivial File
Transfer Protocol (TFTP) or File Transfer Protocol (FTP) to transfer the files
to your TPF system.
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:
- check_helo_acl
- permit_mynetworks
- reject_invalid_hostname
- 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:
- check_client_acl
- permit_mynetworks
- reject_unknown_client
- 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:
- check_sender_acl
- reject_unknown_sendom
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.
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.
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:
- net.work.addr
- net.work
- net
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.