How Can I Change Default Reply ToEmail

I want to set the SMTP settings manually instead of using a plugin. I did this using this resource. However, there is a problem.
If the user clicks “Reply”, a different e-mail appears. Probably I’ve described this before with the plugin. However, I cannot remove it. If I make a new definition as below, it creates a new reply e-mail. Therefore, the past is not erased.
What I want: If the user clicks to reply to the incoming e-mail, only smtp_from e-mail should appear.

Why won’t wp_mail() let me set the From: header when plain old PHP mail() will?

When I use wp_mail( $to, $subject, $message, $headers ) (with values in place, of course), the email gets sent with a from name and email that isn’t set anywhere I can find (not even in PHP or Apache settings). However, using mail( $to, $subject, $message, $headers ) instead works just fine. What could be happening with wp_mail() to cause this?

Sending multipart (text/html) emails via wp_mail() will likely get your domain banned

Summary Because of a bug in WP Core, sending multipart emails (html/text) with wp_mail() (to reduce chance of emails ending up in spam folders) will ironically result with your domain being blocked by Hotmail (and other Microsoft emails). This is a complex problem that I’ll aim to break down in great detail in an attempt … Read more