Thanks Greenreader9, I actually set up to 2 minutes to try whether cronjob is working or not, so 2 minutes is not ultimate choice of mine.
I read all those options about mailing : How to send email with Gmail SMTP and sample contact form in GitHub - InfinityFreeHosting/contactform: Simple contact form with PHPMailer. However, it requires new gmail account etc. . I will try to solve that “cron job”. Thanks for all efforts to help.