While it would be great to assume writers are also excellent spellers, it simply is not always the case.  You can either make a great impression or a poor one with great writing and poor spelling.  I use the following tips to make sure the two are practically seamless;  use spell check when possible especially on a computer, print out a hard copy when available and proof before sending, step away from it for 15 minutes and my favorite; read it backwards-it works!  LA Carlson