Add reply by email link to RSS feed for each post

I came across this post where author added mailto email link to each blog post in RSS

As per that portion of XML output looks like this:

........<p><a href="“Bookiversary.”">Reply via email</a></p> </content>

I don’t know PHP - just some basics I learned by dealing with WordPress, however, I become curious how it was done and after some googling I came across the following PHP snippet from

I don’t need the part of the script that deals with comments ( I have commenting off). I am only trying to implement the portion that pulls in post title with get_the_title()

// add 'reply via email' to all RSS feeds
function add_content_to_all_feeds($content) {

	  $after = '<p><a href="' . str_replace(' ', '%20', get_the_title()) . '%22">Reply via email</a></p>';

	if (is_feed()) {

		return $content . $after;

	} else {

		return $content;

add_filter('the_content_feed', 'add_content_to_all_feeds');

and gives the following output:

<p><a href="">Reply via email</a></p>]]></content:encoded>

Question: In the above output (first link) the post title is output surrounded by double quotes “Bookiversary.” and in my output it is surrounded by %22 - it appears it is not converted into double quotes. Why?