Learn Spanish (Latin America): Es necesario que despaches el paquete temprano. - It is necessary that you dispatch the package early.

The phrase Es necesario que (It is necessary that) is an impersonal expression that states a requirement or recommendation. In Spanish, these expressions always trigger the subjunctive mood in the following verb because they express what should happen rather than stating a concrete, established fact.

Could I use envíes or mandes instead of despaches here?

Yes, absolutely! Enviar and mandar are very common everyday words for "to send." Despachar means "to dispatch" or "to ship" and is often used in business contexts, at a post office, or when talking about officially sending off goods and packages.

Why is it temprano and not tempranamente to say "early"?

While tempranamente exists, temprano functions as both an adjective and an adverb. Native speakers almost exclusively use temprano as the adverb when talking about doing something early in the day or ahead of time.