How to display a different sender's email in a letter?

Question

SMTP

Actually a question in field substitution from.
If you simply replace it, then there will be problems with delivery on domains where the spf record is configured.
I tried the reply-to option.
Yes, when you click to answer, the desired email is substituted, but before that, the wrong email is lit.
What other options are there?

Answer 1

> problems with delivery on domains where the spf record is configured.
It has nothing to do with it. "Problems" you have because of correctly configured mail servers on the receiving side.
The rest of your question is: "How do I send spam, and that I get nothing for it." The answer is no. Send emails from your own From, configure your mailer to work with this From, and everything will be fine.