I was applying for a job and the HR person replied to me. I replied back regarding some questions asked. From the name, I inferred that the person was a man and replied with
Dear Mr. ABC,
Later in the day I looked up the person's profile on the internet only to discover that they are actually a woman! What should I do now? What should I say to her?
I have learned my lesson to actually look up the person in the conversation first.