Emailed photos are small no mattt size I choose in export dialogue box

Question

E

Answer 1

LR is working on the uncompressed data inside of itself so the relative size between originals and exported size is determined entirely by what you do to the JPGs as you process and the export settings.
If you’re reexporting your JPGs without resizing them, then the Quality setting has the most effect on increasing or decreasing the size relative to what was imported. 
Also, making them smoother (using noise-reduction) will also help them compress more, and making them less smooth (adding sharpening) will prevent them from being compressed as much for a given quality setting.
JPGs lose quality when you compress them so the trick is to compress them enough to make them a manageable size without degrading them too much.   Export your images as uncompressed 8-bit TIFs to see what the JPG compression is accomplishing.
Increasing the quality setting higher than 70 will make them larger so you can experiment with multiple quality settings to gauge what quality the originals were created using. 
For your experiments to be most accurate you’d want to export the JPGs without any other processing having been applied: no toning or noise-reduction or sharpening or resizing.  Once you determine what quality setting gives a similar size to what was imported you can then decide if you want to make them smaller to keep your e-mail size manageable, comparing the quality of the files, visually, instead of just relying on size to know if they have similar quality.
LR may use slightly different JPG compression methods than what produced the JPGs in the first place, so don’t be too obsessed with them being exactly the same size, just roughly the same magnitude.