SMTP(S)
Simple Mail transfer Protocol
InBound Mail = POP3(S) - IMAP(S)
OutBount Mail = SMTP(S)
- Standard mechanism for sending emails
- Authentication optional
- But definitely recommended
- In the past it lead to a lot of spam
- Clear text
- TCP 25 / TLS 587
- You can still do hashing
- Hashes will be protected by the use of TLS
- TLS tunnel will secure your credentials
- Relaying capabilities
- You may have a server mail environment where you send all your email to, that server will be responsible for the delivery, that's relaying
- MX Records point here!
SMTP Overview
- Send a message to you@pearson.com
- Looks at the domain name and performs an MX Record
- In the Domain Name Service (DNS)
- An MX Record stands for Mail Exchanger
- Points to the IP address of the Mail Server
- An A record matches an IP to a domain with IPv4
- An AAAA record matches an IP to a domain with IPv6
- An MX Record stands for Mail Exchanger
- In the Domain Name Service (DNS)
- Do a DNS lookup through UDP port 53
- Where is the MX record for pearson.com?
- If you have mail to be delivered to anybody, send it to the IP address that the MX record says
- At this point we are going to connect to that server through the default port number for SMTP (25)
/CAP/Network+/Visual%20Aids/Pasted%20image%2020250124152444.png)