Hi @Paolino1980 -
It looks like the string you are creating in your String Input node is malformed for what you’re trying to do. Yours looks something like this (obfuscated for security reasons):
\\domain.com\dir1\dir2\MyReport.pdf
That .com in there looks a little strange. You want to make sure that this URL points to an actual file that the server can locate in its own directory structure.
You may want to check this forum post and the associated workflow on KNIME Hub for an example of how to use the Send Email node. Note that this example still uses local file paths (e.g. file:/C:/myfile.txt) so you stilll will need to come up with a URL that works for your server.