Email - SendMail - Verses EMail field triggering local email client

So as I have been using Ninox a number of years now. I thought it about time I asked on of those stupid questions!

Every day I send various emails to clients - using SendEmail every day. It works fine for the layout style etc I need and to add attachments

However for new clients I want to certain letters go out via my own mail client ie Outlook

Now I can pass the text and variable data by inserting the base letter email and body vlaues of the email field but I would like to pass some HTML styling ie bold etc. which does not seem to work

thus 

Dear {Contact} - works

but <b> Hello </b> don't work

and neither can i add an attachment

is any one passing styled data to their email client okay

 as stated all my other emails via sendEmail are now quite sophisticated and good fro most pat. But i have a few Occasion where I would like o send my email client and I don't wnat to have to sit there restyling what has just opened.