Which statement is true about the function of SMTP?

The function of SMTP, which stands for Simple Mail Transfer Protocol, is primarily focused on the transmission of emails across different servers. It enables the routing of emails between servers, facilitating the movement of messages from the sender's email server to the recipient's email server. This routing capability is essential for email communication on the Internet, as it ensures that emails are properly directed to their intended destinations.

In the context of email systems, SMTP operates alongside other protocols that handle different aspects of email management, such as POP3 or IMAP, which are responsible for retrieving emails from the server. This highlights that SMTP is specifically designed for sending emails and does not perform the function of receiving emails directly from clients. The notion that SMTP only works for internal communication is inaccurate, as it is used broadly across different networks for external communications as well. Additionally, while SMTP can be used to send newsletters, it serves a far broader purpose in the overall email transmission ecosystem than merely that singular application.