As you are aware we are using Mail.dll to connect via POP3 and let us know if you have any experience or sample code snippet for connecting with Gmail account. Thanks!
Enable POP3 in Gmail: https://www.limilabs.com/blog/enable-pop3-in-gmail
Gmail’s POP3 behavior: https://www.limilabs.com/blog/gmail-pop3-behavior
Download emails from Gmail via POP3: https://www.limilabs.com/blog/download-emails-gmail-pop3
I strongly advise using IMAP, as it is newer protocol, and has more features.