>>Hi everybody,
>>
>>I'm writing a letter to Lauren and need to know how to proper address this person. I started Dear Sir, but then had second thought.
>>
>>What do you think?
>
>May not apply in your case, but if you *heard* the name "Lauren" rather than saw it spelled out somewhere, it might actually be "Lorne" - which would almost certainly be male.

No, I saw it written. I'm almost positive that we're speaking about female, but in any case, I forgot where exactly I saw that position. I need to search for it again. I guess if I find it I would write Dear Ms. ... with 2% probability of a mistake.