It looks like this doesn't work. Out of 20 images in my email, only three (the ones with spaces in filenames) were omitted. What preg should I change to make these included too, does anybody know?
I apologize for not specifying before: I'm using FileEmbedder plugin, I'm not doing anything, I believe the pattern is bad, the one that grabs image URLs...
Spaces shouldn't affect it. It's looking for all bytes in the ascii range by default. More likely an incorrect file path would affect it. What does realpath() show? Also is this a remote file (over HTTP/FTP) or a local file on disk?
In that case you can't legally have spaces in the filename since URLs should never contain spaces. urlencode() the path, or replace your spaces with "+" or "%20".