Sendmail or Php Mail Configuration

Hello everyone, I have some confusion regarding email configurations. I have configured settings of SMTP mail setting in Email module inside Setting and it works fine but I am not able to send mail when I change protocol from SMTP to Sendmail or Php mail.

Any idea?

What happens instead?

Hello Denis, Thanks for the reply.

I got error message like :
Expected respnse 220 but got code "" with message "".

Hello, I installed Akaunting free software. But I am unable to send mail by PHP mail or sendmail. When I send mail, it has been sent but not deliver to the customers. Is there any solution of it?

I am running into the same problem. Did you resolve this?