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
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_recipient_limit parameter? And what is the default value for this parameter?
The smtpd_recipient_limit parameter can limit the number of recipients allowed in a single incoming message.
The default value for this parameter is 1000.
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.
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.
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.
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.
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.
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.
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.
Submitted By:-Swati Rana Email-ID: – swatirana@live.com
