As part of the API changes made in the new Windows Phone 8.1 XAML programming model, the EmailComposeTask - and several other tasks - that were available in the Microsoft.Phone.Tasks namespace in Windows Phone 8 are no longer available.

Most of these have been replaced with a new way of performing the same tasks. For sending an email from within your app, the old way in Windows Phone 8 was as follows:

OLD WAY
========

EmailComposeTask emailComposeTask = new EmailComposeTask();
emailComposeTask.Subject = "Subject";
emailComposeTask.To = "support@developer.com";
emailComposeTask.Show();

 
The new way in Windows Phone 8.1 to send an email from your app is as follows:
 
NEW WAY
=========
 
// Define Recipient
EmailRecipient sendTo = new EmailRecipient()
{
    Name = "Name of Recepient",
    Address = "support@developer.com"
};
 
// Create email object
EmailMessage mail = new EmailMessage();
mail.Subject = "this is the Subject";
mail.Body = "this is the Body";
 
// Add recipients to the mail object
mail.To.Add(sendTo);
//mail.Bcc.Add(sendTo);
//mail.CC.Add(sendTo);
 
// Open the share contract with Mail only:
await EmailManager.ShowComposeNewEmailAsync(mail);
 
 
Have fun,
Paras Wadehra
Microsoft MVP - Windows Platform Development
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