202-450 Exam Dumps : LPIC-2 - Exam 202 (part 2 of 2), version 4.5

Sieve is a language for filtering and sorting email messages on a mail server. Sieve core filters are the basic actions that can be applied to a message that matches a set of conditions. The following actions are available in Sieve core filters:

• discard: This action discards the message silently, without sending any notification to the sender or the recipient. This action is useful for deleting spam or unwanted messages.
• fileinto: This action delivers the message to a specified mailbox. The mailbox can be an existing one or a new one that is created by the action. This action is useful for organizing messages into different folders based on their content or headers.
• reject: This action rejects the message and sends a notification to the sender with a specified reason. The message is not delivered to the recipient. This action is useful for informing the sender that the message was not accepted due to some policy or error.

The other options are not valid actions in Sieve core filters. drop, relay, and fileinto are not recognized keywords by Sieve.

References:

• Sieve: An Email Filtering Language, section 2.10, “Actions”
• Sieve Tutorial, section 4, “Actions”

The doveadm who sub-command shows information about the currently connected users and their sessions. The output includes the following columns:

• user: The username of the connected user.
• ip: The IP address of the client.
• port: The port number of the client.
• service: The name of the Dovecot service, such as imap, pop3, lmtp, etc.
• protocol: The protocol version used by the client, such as IMAP4rev1, POP3, etc.
• pid: The process ID of the Dovecot process that handles the connection.
• type: The type of the connection, such as tcp, ssl, etc.
• state: The state of the connection, such as running, idle, etc.
• since: The time when the connection was established.

References:

• doveadm-who - Dovecot Wiki
• LPIC-2 exam 202 objectives, topic 211.3, “Managing Mailbox Access”

 Reverse DNS queries are used to find the domain name associated with an IP address. To perform reverse DNS queries, DNS servers use a special type of record called PTR (pointer) record. A PTR record maps an IP address to a hostname in the reverse lookup zone. For example, a PTR record for the IP address 185.230.63.186 would point to the hostname unalocated.63.wixsite.com. Reverse DNS queries are useful for validating email servers, troubleshooting network problems, and identifying malicious hosts. References:

• 2 Ways to Perform Reverse DNS lookups in Linux - howtouselinux
• Linux managing DNS servers (LPIC-2) · GitHub
• LPI Linux Certification/LPIC2 Exam 202/DNS - Wikibooks