Quick answer
Open with Уважа́емый Ива́н Петро́вич, close with С уваже́нием. Name and patronymic, not first name alone.
The email
The office
Getting things done
A short email
Прошу́, not хочу́
Business Russian uses прошу́ (I request) where English uses “could you”: Прошу́ уточни́ть, прошу́ согласова́ть. It sounds formal rather than bossy, and leaving it out makes a request read as an order.
The formality gap
English business writing has got steadily more casual; Russian has not. До́брый день is an acceptable opener with people you write to often, but Приве́т belongs to colleagues you know well. And the first name alone, without the patronymic, is normal only among younger colleagues in IT and similar fields.
Typical mistakes
Приве́т, Ива́н! — to a new client
Уважа́емый Ива́н Петро́вич,
A first contact is formal.
в вложе́нии
во вложе́нии
в becomes во before в and some clusters.
Check yourself
How do you close a formal Russian email?