Paid Smtp vs phpmailer

Question

Some people pay for smtp for sending mails, and phpmailer could be use with gmail smtp without paying, i don't which one is preferable and why it is preferable? Is there any advantages of one over the other?

Answer 1

It sounds like you're asking for the trade-offs between connecting with a free gmail service for sending email or a paid SMTP service.
PHPMailer isn't an alternative to paid SMTP. PHPMailer is a PHP library that helps your code connect with some SMTP service which could be gmail or something else that you pay for.
gmail offers less privacy than some paid SMTP services. Advertising and sharing some marketing-related information about you is how they make enough money to offer it free. That's the main reason a lot of my projects used other SMTP services.
Paying for SMTP can be very inexpensive for high volume. It could be in the order of $10 for 50,000 emails.
For larger projects, I would generally connect with a gmail account for an initial implementation phase of a project and then switch to a paid SMTP service when real customers may be getting sensitive private information passing through the service.
For smaller projects, I have always kept using free SMTP services like a gmail account. I created a website for a small business that heavily relied on Google's GSuite services and never paid for an SMTP service. The privacy concerns with gmail were minimal since Google services were already heavily trusted for information in Google Calendar.
This discussion is somewhat related to your question except it is related to more comprehensive email services for non-developers:
https://www.quora.com/Why-do-some-people-still-pay-for-their-email

Answer 2

Okay privacy issues with google , now i understand