Can't be done natively.
You'll need a plugin to do this. Off the top of my head, MonkeyBreadSoftware and 360Works both provide this.
Your only option to do this natively is to merge the PDF's using the 'Append to PDF' option when creating the second PDF.
FileMaker, as standard, only allows a single attachment when sending emails, as well as the emails being in plain text (non html).
You have two options:
1) If you want to be able to send multiple attachements, then you will need to use a thid party plug-in, and there are a few that enable multi attachements. A quick search will give you some suggestions.
2) If you do not want to have to use a third party plug-in, you would merge the two seperate pdf's that you have created into one single pdf (by using the append option in the pdf creation script stop options when creating the second pdf). However, it looks like you are trying to email pdf's that are already created and not generated by FileMaker?, in which case this may not be an option for you in your example.
Thank you all for the prompt replies
We have 360 works scribe so I will look into that
Have a nice day
Just found that out
Will probably get that too
Here is an explantation on how to send email via MBS Plugin:
This includes multiple attachments from file/container/text, multiple recipients, custom headers, plain and html text, inline graphics and TLS 1.2 encrypted connection to server.