Smtp port mail

SMTP (Simple Mail Transfer Protocol) is a protocol used for sending and receiving email messages over the internet. The standard SMTP port is:

• Port 25: This is the default port used for sending and receiving email messages. However, some email providers and ISPs may block or restrict access to this port for security reasons.

Other SMTP ports that are commonly used:

• Port 587: This is a submission port used for sending email messages from a mail client or webmail interface. It is often used by email providers to allow users to send email messages from their accounts.
• Port 2525: This is an alternative port used for sending email messages, especially for those who are behind a firewall or have restrictions on port 25.
• Port 465: This is a deprecated port that was previously used for SMTPS (SMTP over SSL/TLS), but it is no longer recommended for use.

SMTP authentication:

• SMTP authentication is used to verify the identity of the sender and ensure that only authorized users can send email messages. The most common authentication methods used in SMTP are:
  • Plain Text Authentication: This method sends the username and password in plain text over the network.
  • CRAM-MD5 Authentication: This method uses a challenge-response authentication mechanism to verify the identity of the sender.
  • DIGEST-MD5 Authentication: This method uses a challenge-response authentication mechanism with a hash function to verify the identity of the sender.

SMTP encryption:

• SMTP encryption is used to secure the transmission of email messages over the internet. The most common encryption methods used in SMTP are:
  • SSL/TLS (Secure Sockets Layer/Transport Layer Security): This method uses a cryptographic protocol to encrypt the data transmitted over the network.
  • STARTTLS: This method is an extension of the SMTP protocol that allows for the encryption of email messages using SSL/TLS.

SMTP commands:

• SMTP commands are used to send and receive email messages over the internet. The most common SMTP commands are:
  • HELO/EHLO: This command is used to initiate a connection with an SMTP server and identify the sender.
  • MAIL FROM: This command is used to specify the sender's email address.
  • RCPT TO: This command is used to specify the recipient's email address.
  • DATA: This command is used to send the email message.
  • QUIT: This command is used to terminate the connection with the SMTP server.

SMTP responses:

• SMTP responses are used to indicate the status of an email message. The most common SMTP responses are:
  • 250: This response indicates that the email message was successfully received.
  • 550: This response indicates that the email message was rejected due to a problem with the sender's email address.
  • 421: This response indicates that the email message was temporarily rejected due to a problem with the sender's email address.
  • 554: This response indicates that the email message was permanently rejected due to a problem with the sender's email address.