Pages

Can anybody please help me !!

I use pages a lot for sending quotations to customers via email. Sometimes after a few weeks the customer asks me to edit the quotation.

Is there an actual way I can export the pages document from my email back to pages?? I have tried many times and can’t find a way, it is so frustrating as I then have to write the whole quotation from scratch again just because I wanted to edit it slightly. Please help.