EF Problems with Navigation Properties and Mapping - entity-framework-4.1

Question

At start i wanted to mention that i've been fighting this thing for a few days and tried many of the answers more or less related to this problem. Yet I could not resolve it.
I have two classes that represent tables in a DB. These are the existing tables used by legacy application and I cannot change them.
Message can have multiple MessageRecipients.
Environment: MVC3, EF4.1
Classes are:
public class Message
{
[ForeignKey("MessageReciepients")]
public virtual int MessageID { get; set; }
public string Title { get; set; }
public string Content { get; set; }
public DateTime Recieved { get; set; }
[ForeignKey("User")]
public int AuthorUserID { get; set; }
//P\\ Navigation properties
public virtual IList<MessageRecipient> MessageReciepients { get; set; }
public virtual User User { get; set; }
}
public class MessageRecipient
{
//[Key]
[DatabaseGenerated(DatabaseGeneratedOption.None)]
public int MessageID { get; set; }
public int UserID { get; set; }
public bool Read { get; set; }
public bool Important { get; set; }
public bool Deleted { get; set; }
public bool Destroyed { get; set; }
//P\\ Navigation Properties
public virtual User User { get; set; }
}
The error I have is:
The foreign key component 'MessageID' is not a declared property on
type 'MessageRecipient'. Verify that it has not been explicitly
excluded from the model and that it is a valid primitive property.
How to correctly map these classes, relationships to load the recipients of a message?
I can add that the navigation property User works correctly for a Message and loads a User's data correctly.
I'm not too experienced with .NET and I learn while doing this.
I tried some EF API config to map these i tried swearing at it, curse it, and been close to cry and pray at the same time. No Joy!!
I would really appreciate the help.

Answer 1

It turned out that the problem was with the composite key that i needed to use and it all could be solved with some attributes:
This is how it looks now:
public class Message
{
public int MessageID { get; set; }
public string Title { get; set; }
public string Content { get; set; }
public DateTime Recieved { get; set; }
[ForeignKey("User")]
public int AuthorUserID { get; set; }
//P\\ Navigation properties
public virtual ICollection<MessageRecipient> MessageRecipients { get; set; }
public virtual User User { get; set; }
}
public class MessageRecipient
{
[Key, Column(Order=0), ForeignKey("User")]
[DatabaseGenerated(DatabaseGeneratedOption.None)]
public int UserID { get; set; }
[Key, Column(Order = 1)]
[DatabaseGenerated(DatabaseGeneratedOption.None)]
public int MessageID { get; set; }
public bool Read { get; set; }
public bool Important { get; set; }
public bool Deleted { get; set; }
public bool Destroyed { get; set; }
//P\\ Navigation Properties
public virtual User User { get; set; }
}

Answer 2

fill in the missing properties:
public class Message
{
public int MessageID { get; set; }
}
public class MessageRecipient
{
public int MessageID { get; set; }
[ForeignKey("MessageID")]
public Message Message { get; set; }
}