This is a very high level and very simplified overview of how email gets to the person you are sending it to. This article is not meant to provide all of the nitty-gritty technical details, it is just the basics to give you an indication of what is involved. If you want to know more then Google is your friend 🙂
- Email is sent from servers.
- Websites live on servers and servers are identified by IP (Internet Protocol) addresses.
- An IP address is a series of numbers.
- Domain names need a protocol call DNS (Domain Name System) to enable people to find the website.
- DNS converts the domain name to the IP address numbers
- There are two formats for IP address numbers IPv4 & IPv6
e.g. domain name example.com = 93.184.216.34 ( IPv4 format = xxx.xxx.xxx.xxx) - Servers use name server (NS) records to tell other servers what domain names are available on what server.
- Each domain name has a zone file record
- A domain zone file can have multiple records.
- examples are ‘A records’ and ‘MX records’
- An A record is the actual record that points example.com to 93.184.216.34
- An MX-record (Mail eXchange-record) states what specific IP address emails need to be sent to and possibly set a priority if you have two or more mail servers.
- When you send an email to ‘somebody@…’ the sending server converts the domain name element (example.com) to the IP address
- It contacts the IP address and ‘asks’ if the server at the IP address accepts emails for the domain name (example.com).
- The receiving server says Yes or No
- If the answer is ‘Yes’ the the sending server sends the email – if the answer is ‘No’ the email is not sent
- If the email is sent then the receiving server will try to add the email to the mailbox of the recipient
- Depending on the success or failure of every attempt to send and or deliver email the server(s) will send a ‘response message‘
- The response message can be: Success, Failure, Deferred (will continue to try)
- Failure messages (AKA Bounces) are either Total (hard bounce) or Temporary (soft bounce)