It’s always been true in business, people like to deal with real
people.
When you’re sending an email to get a message across, you should
find and use a ‘voice.’
Your voice.
So if you’re funny, be funny.  If you are hip, be hip.  If you are a detail person, be precise. Use language and expressions you would use if we were talking in person. And for heaven’s sake, if you went to an English boarding school, you shouldn’t write emails.  Hire someone to write them for you!
Whatever characteristics you have that make you unique, you should use in your emails.
One mistake I see all too often is that emails are written in a very
formal, proper manner.
That takes you away from connecting with people.  And connecting
with people is one of the primary advantages of email.
Make sure you take advantage of it.