I know this is possible to send mail through "PHPMailer" by using SMTP of a personal address. (By creating a personal Gmail or yahoo address, and by using PHPMailer to send emails through this address in SMTP).
What is the deliverability rate of this sending method? Is it equal to a professional offer on a service like SendGrid?
When I send my mail from Gmail or Yahoo there are not blocked. Also by using Gmail in SMTP the result would be the same not?
(Edit : I speak about 10 000 mails sent in one day and not only transactional email.)