You can bypass client-side email software such as OUTLOOK if the PDF submits to a server-side script, such as ASP.net or PHP. ASP.net scripts are capable of merging and parsing the form submission using iText and/or FDFToolkit.net, and inject the values into the message body, subject, TO, CC, BCC, and attachment file name. PHP script are not compatible with iText technologies, so you receive a static message and attachment. Submitting to a server-side script is more reliable, because, it silently sends the submission using an SMTP account, and doesn't require end-users to setup their client-side email software.
Note: iText technologies are not compatible with LiveCycle PDF forms saved as "dynamic PDF"; but, have limited compatibility with static LiveCycle XFA PDFs, and iText is full compatibility with Acrobat PDFs.
Visit the following website for online examples:
www.pdfemail.net/examples/