Send mail sends plain text to the recipient. It can't send a "current record". You can either set up a calculation for the body of the email that combines data from various fields in the current record or you can attach either a PDF or a snap shot link as an attachment to the email.
Thus, many FileMaker scritps for emailing data first use save as PDF to generate a pdf of the record and a specific layout and then attach that PDF to the email.
There are also a number of plug ins that offer additional options for sending email from FileMaker that you can web search and evaluate.