Speaking of Best Practices…
Answering the email from the GPM – do I have to do it right away?
The answer is ‘yes.’ As soon as possible!
In a five-language project, apart from the internal resource (localization engineer), the Global Project Manager (GPM) deals with at least five different contacts in the respective offices. This is because the person who responds to the initial email might not be the one who will communicate with the GPM after the project has been approved.
I have managed projects in which I received emails from three different people in the same office who were in charge of a single language. Moreover, the GPM exchanges messages with the client, sometimes with the client’s developer, and often with the translators, who should communicate only with the LPMs. Here is a rough calculation: if there is only one translator per language, we will have 12 people writing compulsively and only one, poor GPM to answer them all. 
Therefore, my dearest LPM, whenever you receive a heads up or handoff email from your GPM, make sure you answer it asap. It may seem a trivial matter, but your answer can make a whole lot of a difference in the success of a project planning, especially if there are 25 languages involved and a list of additional activities and resources that you had no idea they existed.