Q: - What is the location of postfix mailserver Queue ?
By default, the Postfix mail queues are located in the /var/spool/postfix directory. Each
message queue is created as a separate subdirectory within this directory. Each message is stored as a separate file in the subdirectory, using a unique identifier for the filename.
By default, the Postfix mail queues are located in the /var/spool/postfix directory. Each
message queue is created as a separate subdirectory within this directory. Each message is stored as a separate file in the subdirectory, using a unique identifier for the filename.
Q: - What is LMTP ?
The Local Mail Transport Protocol (LMTP) is a different mail transport protocol described in RFC 2033. LMTP utilizes a set protocol similar to SMTP for delivering messages to the local host. Postfix can be configured to deliver messages to local users using LMTP if desired.
Q: - What is canonical Table ?
The cleanup program uses the canonical table to rewrite message addresses contained in the message header.The mail administrator can use one canonical lookup table for both received messages and sent messages or separate tables for each. The canonical table is often used in conjunction with the alias file to provide address header rewriting of outgoing mail messages.
The cleanup program uses the canonical table to rewrite message addresses contained in the message header.The mail administrator can use one canonical lookup table for both received messages and sent messages or separate tables for each. The canonical table is often used in conjunction with the alias file to provide address header rewriting of outgoing mail messages.
Q: - Who is the creater of Postfix ?
Wietse Venema wrote Postfix as a complete MTA package
Wietse Venema wrote Postfix as a complete MTA package
Q: - What is the difference between postfix and sendmail ?
The main difference between Postfix and Sendmail is Postfix’s modularity. Just as the Unix system broke up e-mail functionality between modules, Postfix extends that practice to the MTA program. Postfix uses several different programs to implement the MTA functionality.This allows each modular program to be smaller and quicker than one large monolithic program would be.
Postfix is more secure than sendmail.Postfix requires a separate userid to be added to the mail server. Each module runs under this userid. If an intruder compro-mises a Postfix module, he most likely will still not be able to break out of the module
and gain control of the mail server.
and gain control of the mail server.
Instead of one large compiled configuration file, Postfix uses multiple files that use plaintext parameter and value names to define functionality. Most of the parameters used in Postfix default to common-sense values that allow the mail administrator to configure a complete mail server with a minimal amount of effort.
Q: - what is qmgr ?
Once the valid message is rewritten and placed in the incoming message queue, the qmgr program ensures that the message is delivered to the proper destinations. The qmgr program then examines message headers and passes them to the appropriate delivery program depending on the destination addresses. Currently, the qmgr program can forward messages to the local, smtp, and pipe programs.
Once the valid message is rewritten and placed in the incoming message queue, the qmgr program ensures that the message is delivered to the proper destinations. The qmgr program then examines message headers and passes them to the appropriate delivery program depending on the destination addresses. Currently, the qmgr program can forward messages to the local, smtp, and pipe programs.
Q: - Tell me about latest Version of Postfix on which u have worked ?
postfix 2.6
postfix 2.6
Q: - What are the important files for postfix server ?
/etc/postfix/main.cf
/etc/postfix/access
/etc/postfix/aliases
/etc/postfix/main.cf
/etc/postfix/access
/etc/postfix/aliases
Q: - Where postfix mail server logs created ?
/var/log/maillog
/var/log/maillog
Q: - Explain the working of local mail submission for postfix?
When a local email message enters the postfix system. Local messages are deposited into the maildrop directory of the Postfix queue by the postdrop command, usually through the sendmail compatibility program. The pickup daemon reads the message from the queue and feeds it to the cleanup daemon. The cleanup daemon processes all inbound mail and notifies the queue manager after it has placed the cleaned-up message into the incoming queue. The queue manager then invokes the appropriate delivery agent to send the message to its next hop or ultimate destination.
Q: - What are the benefits of using SMTP AUTH?
- Using SMTP AUTH we can make it possible for clients, colleagues, and ourselves to relay messages from everywhere in the world using only one (our) SMTP server.
- Being a mobile user, we don't have to deal with the hassle to find a SMTP server that permits us to relay.
- We can make use of scripts and daemons that run on our server and provide services that we need e.g. server-side virus scanning.
- Using SMTP AUTH we can make it possible for clients, colleagues, and ourselves to relay messages from everywhere in the world using only one (our) SMTP server.
- Being a mobile user, we don't have to deal with the hassle to find a SMTP server that permits us to relay.
- We can make use of scripts and daemons that run on our server and provide services that we need e.g. server-side virus scanning.
Q: - by using postconf command, how you will set fully qualified hostname (mail4.test.com)?
# postconf -e myhostname=mail.example.com
# postconf -e myhostname=mail.example.com
The -e option tells postconf to edit the configuration with the parameters and values specified.
Q: - Which command checks for configuration problems?
# postfix check
# postfix check
Q: - How you will see the queue of postfix server?
#postqueue -p
#postqueue -p
Q: - How can I clear postfix mail server queue?
# postsuper -d ALL
# postsuper -d ALL
Q: - How you will reload the postfix queue?
# postsuper -r ALL
# postsuper -r ALL
Q: - Can postfix server configured with MySQL database?
Yes
Yes
Q: - which command is used to find out that postfix is complied with mysql or not?
# postconf –m
# postconf –m
nis
regexp
environ
mysql
btree
unix
hash
regexp
environ
mysql
btree
unix
hash
Q: - What steps required to get Postfix to connect to the MySQL database?
- define the MySQL alias_maps entry in the main.cf configuration file
- define the MySQL alias_maps entry in the main.cf configuration file
alias_maps = hash:/etc/postfix/aliases, mysql:/etc/postfix/mysql-aliases.cf
- The configuration file mysql-aliases.cf defines the parameters necessary for postfix to connect to the MySQL database.
Q: - Explain smtpd_timeout Parameter?
The smtpd_timeout parameter limits the amount of time Postfix waits for an SMTP client request after sending a response. This allows the Postfix administrator to quickly disconnect SMTP servers that “camp out” on the SMTP connection, utilizing system resources for the SMTP connection without actually sending a message.
The smtpd_timeout parameter limits the amount of time Postfix waits for an SMTP client request after sending a response. This allows the Postfix administrator to quickly disconnect SMTP servers that “camp out” on the SMTP connection, utilizing system resources for the SMTP connection without actually sending a message.
smtpd_timeout = value
By default, Postfix will assume the value is in seconds.
Q: - Explain queue_run_delay Parameter?
The queue_run_delay parameter sets the time interval (in seconds) that Postfix scans the deferred message queue for messages to be delivered. The default value for this is 1,000 seconds.
The queue_run_delay parameter sets the time interval (in seconds) that Postfix scans the deferred message queue for messages to be delivered. The default value for this is 1,000 seconds.
Q: - Explain maximal_queue_lifetime Parameter?
The maximal_queue_lifetime parameter sets the amount of time (in days) that a message remains in the deferred message queue before being returned as undeliverable. The default value is 5 days. Once this value is reached, Postfix returns the message to the sender.
The maximal_queue_lifetime parameter sets the amount of time (in days) that a message remains in the deferred message queue before being returned as undeliverable. The default value is 5 days. Once this value is reached, Postfix returns the message to the sender.
Q: - Explain minimal_backoff_time Parameter?
The minimal_backoff_time parameter sets one value that has two uses: the minimum amount of time used to hold a message in the deferred message queue and the minimum amount of time for which a host can be marked unreachable. The default value for this parameter is 1,000 seconds.
The minimal_backoff_time parameter sets one value that has two uses: the minimum amount of time used to hold a message in the deferred message queue and the minimum amount of time for which a host can be marked unreachable. The default value for this parameter is 1,000 seconds.
Q: - Explain maximal_backoff_time Parameter?
The maximal_backoff_time value sets an upper limit to the amount of time a message is left in the deferred message queue without a delivery attempt. The default value for this parameter is 4,000 seconds.
The maximal_backoff_time value sets an upper limit to the amount of time a message is left in the deferred message queue without a delivery attempt. The default value for this parameter is 4,000 seconds.
Q: - Explain default_destination_concurrency_limit Parameter?
The default_destination_concurrency_limit parameter defines the maximum number of concurrent SMTP sessions that can be established with any remote host. This parameter is related to the SMTP maxprocess parameter in the master.cf configuration file. The maximum number of concurrent SMTP sessions cannot exceed the maxprocess value set for the maximum number of SMTP client processes. Thus, if the default maxprocess value of 50 is used, setting the default_destination_concurrency_limit greater than 50 has no effect.
The default_destination_concurrency_limit parameter defines the maximum number of concurrent SMTP sessions that can be established with any remote host. This parameter is related to the SMTP maxprocess parameter in the master.cf configuration file. The maximum number of concurrent SMTP sessions cannot exceed the maxprocess value set for the maximum number of SMTP client processes. Thus, if the default maxprocess value of 50 is used, setting the default_destination_concurrency_limit greater than 50 has no effect.
Q: - Explain initial_destination_concurrency Parameter?
The initial number of concurrent SMTP sessions Postfix will establish with a remote host is defined by the initial_destination_concurrency parameter. The default value for this parameter is 2.
The initial number of concurrent SMTP sessions Postfix will establish with a remote host is defined by the initial_destination_concurrency parameter. The default value for this parameter is 2.
