Problems related to smtp and pop3 usage in php

Php uses smtp and pop3. I want to use php to implement the post office function. I downloaded hmailserver and a webmail and configured it successfully. when I checked the webmail source code, I found two important classes, one is class. smtp. php, one is class. pop3.php, because the structure of the site is not the problem of using smtp and pop3 in php
To use php to implement the post office function, download hmailserver and a webmail and configure it successfully.

When looking at the source code of webmail, we found two important classes, one being class. smtp. php, one is class. pop3.php, because it is not very familiar with the structure of the site (no documentation, although the structure looks very clear, but there are a lot of data cached in it, so I felt dizzy and couldn't see it anymore)
I searched on the internet and found that these two classes exist in many places. it seems that phpmailer is highly respected. However, I think phpmailer seems to have only smtp but not pop3.

So I would like to ask, what are the ready-made open-source resources for smtp and pop3 implementation?

In this way, I can call smtp and pop3 resources and complete subsequent data processing.

Thank you. Share:
------ Solution --------------------
Https://github.com/PHPMailer/PHPMailer

With POP3