I believe that almost all UX designers have thinked about this question. But UX design is really a complicated work. What should a UX designer know? Programming? Drawing? Design? or Psychology?
Perhaps many designers know much knowledge in the fields above, but they still write e-mails with full of typos or strange formatting. We should realize that the e-mails are our products and the readers are users. We also have to consider our readers when writing e-mails.
Then I found that a good UX designer must be a person who always consider for other people whenever what he does.