If you turn your laptop 90 degrees counter clockwise they will all be left.
But I assume you mean you want the table layout in that email to have the header values align to the left of their cells?
If so it depends on the source that create the email. If it was an incoming mail the damage is done. If you are creating the mail, make sure the HTML code of the table is written with the style element aligning it left. Here it depends on how you define this table. A mere screenshot of the result is somewhat limiting.
Please help what changes i have to make
Somewhere else you are setting the alignment again or the html code is not this as I see text align to be left already in screenshot
cheers
it should be a header tag and please add alignment in it