I am trying to export an image in the following way:
p1 = Plot[Sin[x], {x, -3, 3}]
Export["sinx.jpeg", p1, ImageResolution -> 1200]
The exported image in this case extremely nice.
Where as in the following cases, it is weird!
p1 = Plot[Sin[x], {x, -3, 3}, PlotLegends -> {"sinx"}]
Export["sinx.jpeg", p1, ImageResolution -> 1200]
How to obtain the same high resolution good quality image of the first case in the second one also along with legends?
Surprisingly in none of the exported images, tick marks are not visible where as in the copy&paste images they are visible!
Update: I am working on Version 10.0.2.0
Thank you.

Magnify[p1, 15]is also wrong. Can you upgrade to v10 or v11? – Szabolcs Nov 04 '16 at 11:49