(20250117) Major revamping in the mail module. Everything revamped. Sending is a pending task.

models/core/message.py

@@ -149,12 +149,12 @@ class CoreMessageModel(BaseModel):
         default = False
     )
 
-    sender: str | None = Field(
+    sender: List[str] | None = Field(
         description = "the name of the sender; null if you are the sender",
         frozen = True
     )
 
-    recipient: str | None = Field(
+    recipient: List[str] | None = Field(
         description = "the name of the recipient; null if you are the recipient",
         frozen = True,
         default = None
@@ -260,6 +260,12 @@ class CoreMessageModel(BaseModel):
         except: pass
         return value
 
+    @field_validator("sender", "recipient", mode = "before")
+    def validate_participants(cls, value):
+        if value is None: value = []
+        if isinstance(value, str): value = [value]
+        return value
+
     @field_validator("tags", mode = "before")
     def validate_tags(cls, value):
         if value is None: value = []