Mozilla Thunderbird is a free and open source email client developed by the Mozilla Foundation that can be downloaded at:
To configure Win2PDF to send using Mozilla Thunderbird, first open the "Configure Mail" from the Win2PDF Desktop file menu.
Win2PDF Configure Mail
You can also open "Configure Win2PDF Mail" from the Windows start menu under the "Win2PDF" program group. The following Window is displayed:
Win2PDF Mail Configure Thunderbird
Select "Use Thunderbird" and click OK. The Win2PDF Desktop "Send Mail" and the Win2PDF "Send File" features will now use Mozilla Thunderbird to attach a PDF to a new email message.