I am not a fan of people who boast about themselves. Let your actions do the talking. The only time I think it is fair game is if you are trying to impress a girl in which case say whatever it takes. This leads me to the point of this entry – An Email tool for adding Titles.
Make your email something simple. I automatically think a person who puts there title in their email is a complete tool. Frankly, the chances that person also has a pair of sketcher shoes is very high. I see and know a lot of people who have imbedded dr into their email. Are you that cool? Must everyone know right away that you are a doctor? Does this make you a better person. The obvious thing with emails is to not have something stupid in there if you are going to use it professionally like firstname.lastname@example.org but equally as bad is to have your title. If you are applying for a job, I would hope your resume tells you your profession and/or what are applying for. I will weed you out with a dumb email and putting your title counts. I want smart people who do not have to tell me they are smart.