i.tech assignment

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Internet Technology

Assignment-1

1. html_directory = /usr/share/doc/postfix/html

It is the location of the Postfix HTML documentation. The html file in this location

describes how to bulid, configure or operate a specific Postfix subsystem or feature

2. sendmail_path = /usr/sbin/sendmail.postfix

This is the full pathname of the Postfix sendmail command. A Sendmail compatibility

feature specifies the location of the Postfix sendmail(1) command. This command can be

used to submit mail into the Postfix queue. The Postfix sendmail(1) command implements the

Postfix to Sendmail compatibility interface. By default, Postfix sendmail(1) reads a messagefrom standard input until EOF or until it reads a line with only a . character, and arranges

for delivery.

3. setgid_group = postdrop

This is the group for mail submission and queue management commands. This must be a group

name with a numerical group ID that is not shared with other accounts, not even with the

Postfix account.It gives the group ownership of set-gid Postfix commands and of group-writable

Postfix directories. When this parameter value is changed you need to re-run postfix set-

permissions. The default value is postdrop.

3. command_directory = /usr/sbin

The command_directory parameter speecifies the location of the administrative commands. In

this case these commands are present in /usr/sbin

4. manpage_directory = /usr/share/man

This gives the location of the Postfix on-line manual pages i.e. where the postfix manual pages

are installed.

5. daemon_directory = /usr/lib64/postfix

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The daemon_directory parameter specifies the location of all Postfix daemon programs (i.e.

programs listed in the master.cf file). This directory must be owned by root.These should not be

invoked directly by humans.

6. data_directory = /var/lib/postfix

The data_directory parameter specifies the location of Postfix-writable data files (caches,

random numbers). This directory must be owned by the mail_owner account and must not be

shared with non-Postfix software.

7. newaliases_path = /usr/bin/newaliases

This is the full pathname of the Postfix newaliases command. This command is Sendmail-

compatible to build alias databases.

8. mailq_path = /usr/bin/mailq

This is the full pathname of the Postfix mailq command. This command can be used to list the

Postfix mail queue.

9. queue_directory = /var/spool/postfix

The queue_directory specifies the location of the Postfix top-level queue directory.This is

also the root directory of Postfix daemons processes that run chrooted.

10. mail_owner = postfix

The mail_owner parameter specifies the owner of the Postfix queue and of most Postfix

daemon processes. The name of a user account should does not share its user or group ID with

other accounts and that owns no other files or processes on the system. In particular, don't

specify nobody or daemon.

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11. mydomain = iiitm.ac.in

The mydomain parameter specifies the local internet domain name.

The default is to use $myhostname minus the first component. $mydomain is used as a default

value for many other configuration parameters.

But here the internet domain name is iiitm.ac.in

12. myorigin = $mydomain

The domain name that locally-posted mail appears to come from, and that locally posted mail is

delivered to. When run on a domain with multiple machines, this is changed to $mydomain.

For the sake of consistency between sender and recipient addresses, myorigin also specifies the

default domain name that is appended to recipient addresses that have no @domain part.

13. mydestination =

It Specifies a list of host or domain names, "/file/name" or "type:table" patterns, separated

by commas and/or whitespace. A "/file/name" pattern is replaced by its contents; a

"type:table" lookup table is matched when a name matches a lookup key (the lookup result is

ignored). Continue long lines by starting the next line with whitespace.

14. message_size_limit = 20971520

This is maximal size in bytes of a message, including envelope information.

15. bounce_queue_lifetime = 2d

This is the maximal time a bounce message is queued before it is considered undeliverable. By

default, this is the same as the queue life time for regular mail.

In this command the bounce message will be queued for 2 days before consideringundeliverable

Time units: s (seconds), m (minutes), h (hours), d (days), w (weeks). The default time unit is d

(days).

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16. backwards_bounce_logfile_compatibility = no

This produces an additional bounce(8) logfile records that can be read by Postfix versions

before 2.0. But since this value is NO here therefore no additional bounce(8) logfile record

will be produced.

17. disable_verp_bounces = yes

This disables sending one bounce report per recipient.

18. maximal_queue_lifetime = 2d

This is the maximal time a message is queued before it is sent back as undeliverable. i.e. this

message will be queued for 2 days before being sent back undelivered.

Time units: s (seconds), m (minutes), h (hours), d (days), w (weeks). The default time unit is d

(days).

19. masquerade_domains = !lists.iiitm.ac.in iiitm.ac.in

This gives the optional list of domains whose subdomain structure will be stripped off in email

addresses. The list is processed left to right, and processing stops at the first match.

But a domain name prefixed with ! means do not masquerade this domain or its subdomains.

Hence, the given command will not change "user@anything.lists.iiitm.ac.in"to

"user@lists.iiitm.ac.in"but it will strip "user@anything.iitm.ac.in"to user@iiitm.ac.in

20. mynetworks = 127.0.0.1 192.168.0.105 192.168.1.104 202.3.77.189 smtpin1.mailsecure.in

The mynetworks parameter specifies the list of "trusted" SMTP clients that have more

privileges than "strangers".In particular, "trusted" SMTP clients are allowed to relay mail

through Postfix.

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21. smtpd_banner = $myhostname

The smtpd_banner parameter specifies the text that follows the 220

code in the SMTP server's greeting banner. Some people like to see the mail version advertised.

By default, Postfix shows no version.

22. smtpd_client_restrictions = permit_mynetworks, reject

This command will permit the request when the client IP address matches any network or

network addresses in $mynetworks and the reject code configuration parameter specifies the

response code for rejected requests.

23. transport_maps = hash:/etc/postfix/transport

This gives the optional lookup tables with mappings from recipient address to (message delivery

transport, next-hop destination). When this this feature is used with local files, run

"postmap/etc/postfix/transport" after making a change.