A bounce report, also known as a bounce message or a non-delivery report (NDR), is an automated email message generated by an email server to inform the sender that their email was not delivered to the recipient’s inbox.
Why an email can’t be delivered? When an email is sent, it is routed through various servers before reaching the intended recipient’s mailbox. If there is a problem with the delivery of the email at any point in this process, such as an incorrect email address, a full mailbox, a blacklisted server, or a blocked email domain, the email may “bounce” back to the sender.
An Email Service Provider (ESP) is a third-party company that offers email hosting and management services, allowing users to send, receive, and manage emails. ESPs typically provide services by managing email servers and other related systems.
Who can be an email service provider? An Email Service Provider (ESP) can be any person, company or organization that provides email hosting and management services. This can include:
Single person running an email server for him/her or a group of persons like family.
Geofeed is a collection of IP networks accompanied by geolocation information that is typically distributed in CSV format via an http(s) link. These links are usually exchanged informally among trusted parties.
What is the format of a Geofeed? Geofeeds are published using https URLs using CSV file format. It consists of four values per line:
IP network in CIDR (Classless Inter-Domain Routing) format (e.g. 192.168.1.0/24) Country (optional): defined using a 2-letter ISO 3166-1 country code (e.
An Internet Service Provider (ISP) is a company that provides internet access to customers. It does this by providing a connection to the internet via a network of servers, which allows users to access the web, send emails, and use other internet services. ISPs can be large, national companies or smaller, local providers.
Do ISPs provide email services? Some Internet Service Providers (ISPs) do offer email services to their customers as part of their internet package.
IP blacklisting is a technique used by Internet Service Providers (ISPs) and email providers to block or filter incoming messages from IP addresses that have been identified as sources of spam or other malicious activity. By blocking or filtering messages from these IP addresses, ISPs and email providers can help protect their users from spam and other unwanted email.
IP Blacklisting on local systems IP blacklisting can be applied using configuration files in several different ways, depending on the specific needs of the organization and the type of system that is being used.
A PTR record (Pointer record) is a type of DNS record used to map an IP address to a domain name (e.g. 127.0.0.1 -> localhost). It enables reverse DNS (rDNS) lookup, allowing you to find the associated domain name for an IP address.
What is a Pointer Record (PTR) used for? A PTR record is used for reverse DNS lookups. It associates an IP address with a domain name, enabling identification of the domain name associated with a given IP address.
Reverse DNS (rDNS) is a technique used to map an IP address to a domain name using a Pointer (PTR) record. It involves querying the DNS system in reverse, starting with the IP address, to retrieve the associated domain name(e.g. 127.0.0.1 -> localhost). Reverse DNS is commonly used for verifying server identities, preventing email spam, and troubleshooting network issues.
What is a reverse DNS record used for? A reverse DNS record, also known as a PTR (Pointer) record, is used for reverse DNS lookups.
A Top Level Domain (TLD) is the last segment of a domain name, representing the highest level in the domain name system. It typically consists of two or more letters and indicates the purpose or geographical location of a website or entity. Examples include .com, .org, and .net. TLDs help categorize and organize websites on the internet, facilitating easy navigation and identification.
What are typical popular TLDs and their envisioned use case?