If you have existing email addresses set up, they will stop working when the domain has been transferred. Once transferred, you will have full access to your domain's DNS settings and you will be able to reinstate your email addresses by following our tutorial: Creating email addresses with your domain purchased from Yola.
There are a few points to note:
If you are using an existing email service where you are downloading your mail to your computer, you will need to change settings on your email program as well as on your domain in order to receive your mail. Because your mail is downloaded to your computer, you will not lose any previous emails or contact information.
If you are using a webmail service where you are logging into a website to view your mail, you will be able to add the MX Record they require to your DNS settings once the domain has been transferred. For information on accessing your DNS settings: Managing the domain you bought from Yola
The transfer process may take up to 12 days, but the actual transfer is usually a lot less. We would suggest that you set up your email accounts while you are waiting for the transfer to go through. Then, when you get the message that the transfer is successful, you can go and add the settings to your domain (please make sure that you are using a different email so you receive this notice).