See line 516 of /plugins/PDFReports/API.php
The From is "Piwik Reports" which is loaded from translations. When a custom is logo is used, we could automatically change it to "$WEBSITE_NAME Report" ?
Also allow to overwrite this defaut name in the config file.
(In ) Fix #2787
When using a Custom logo, the "FROM" email name will be "Web analytics reports"
When not using logo (default) the from will still be "Piwik reports"