diff --git a/api/app/domain/entities/__init__.py b/api/app/domain/entities/__init__.py
new file mode 100644
index 0000000..7c2377a
--- /dev/null
+++ b/api/app/domain/entities/__init__.py
@@ -0,0 +1,3 @@
+from sqlalchemy.ext.declarative import declarative_base
+
+Base = declarative_base()
\ No newline at end of file
diff --git a/api/app/domain/models/appointment_files.py b/api/app/domain/models/appointment_files.py
new file mode 100644
index 0000000..8567af3
--- /dev/null
+++ b/api/app/domain/models/appointment_files.py
@@ -0,0 +1,16 @@
+from sqlalchemy import Column, Integer, String, ForeignKey
+from sqlalchemy.orm import relationship
+
+from app.domain.models import Base
+
+
+class AppointmentFile(Base):
+    __tablename__ = 'appointment_files'
+
+    id = Column(Integer, primary_key=True, autoincrement=True)
+    file_path = Column(String, nullable=False)
+    file_title = Column(String, nullable=False)
+
+    appointment_id = Column(Integer, ForeignKey('appointments.id'), nullable=False)
+
+    appointment = relationship('Appointment', back_populates='files')
\ No newline at end of file
diff --git a/api/app/domain/models/appointments.py b/api/app/domain/models/appointments.py
index 29f00fa..dc127e5 100644
--- a/api/app/domain/models/appointments.py
+++ b/api/app/domain/models/appointments.py
@@ -18,3 +18,5 @@ class Appointment(Base):
     patient = relationship('Patient', back_populates='appointments')
     doctor = relationship('User', back_populates='appointments')
     type = relationship('AppointmentType', back_populates='appointments')
+
+    files = relationship('AppointmentFile', back_populates='appointment')
diff --git a/api/app/domain/models/mailing.py b/api/app/domain/models/mailing.py
new file mode 100644
index 0000000..f5ba465
--- /dev/null
+++ b/api/app/domain/models/mailing.py
@@ -0,0 +1,21 @@
+from sqlalchemy import Column, Integer, String, DateTime, ForeignKey
+from sqlalchemy.sql import func
+from sqlalchemy.orm import relationship
+
+from app.domain.models import Base
+
+
+class Mailing(Base):
+    __tablename__ = 'mailing'
+
+    id = Column(Integer, primary_key=True, autoincrement=True)
+    text = Column(String, nullable=False)
+    title = Column(String, nullable=False)
+    datetime = Column(DateTime, nullable=False, default=func.utcnow)
+
+    user_id = Column(Integer, ForeignKey('users.id'), nullable=False)
+
+    user = relationship('User', back_populates='mailing')
+
+    recipients = relationship('Recipient', back_populates='mailing')
+    mailing_options = relationship('MailingOption', back_populates='mailing')
diff --git a/api/app/domain/models/mailing_delivery_methods.py b/api/app/domain/models/mailing_delivery_methods.py
new file mode 100644
index 0000000..3bd3e86
--- /dev/null
+++ b/api/app/domain/models/mailing_delivery_methods.py
@@ -0,0 +1,13 @@
+from sqlalchemy import Column, Integer, VARCHAR
+from sqlalchemy.orm import relationship
+
+from app.domain.models import Base
+
+
+class MailingDeliveryMethod(Base):
+    __tbalename__ = 'mailing_delivery_methods'
+
+    id = Column(Integer, primary_key=True, autoincrement=True)
+    title = Column(VARCHAR(200), nullable=False)
+
+    mailing = relationship('MailingOption', back_populates='option')
diff --git a/api/app/domain/models/mailing_options.py b/api/app/domain/models/mailing_options.py
new file mode 100644
index 0000000..69c27b9
--- /dev/null
+++ b/api/app/domain/models/mailing_options.py
@@ -0,0 +1,16 @@
+from sqlalchemy import Column, Integer, ForeignKey
+from sqlalchemy.orm import relationship
+
+from app.domain.models import Base
+
+
+class MailingOption(Base):
+    __tablename__ = 'mailing_options'
+
+    id = Column(Integer, primary_key=True, autoincrement=True)
+
+    option_id = Column(Integer, ForeignKey('patients.id'), nullable=False)
+    mailing_id = Column(Integer, ForeignKey('mailing.id'), nullable=False)
+
+    option = relationship('Patient', back_populates='mailing')
+    mailing = relationship('Mailing', back_populates='mailing_options')
diff --git a/api/app/domain/models/patients.py b/api/app/domain/models/patients.py
index 4de950e..bd60eb3 100644
--- a/api/app/domain/models/patients.py
+++ b/api/app/domain/models/patients.py
@@ -20,3 +20,4 @@ class Patient(Base):
 
     lens_issues = relationship('LensIssue', back_populates='patient')
     appointments = relationship('Appointment', back_populates='patient')
+    mailing = relationship('Mailing', back_populates='patient')
diff --git a/api/app/domain/models/recipients.py b/api/app/domain/models/recipients.py
new file mode 100644
index 0000000..607ab04
--- /dev/null
+++ b/api/app/domain/models/recipients.py
@@ -0,0 +1,16 @@
+from sqlalchemy import Column, Integer, ForeignKey
+from sqlalchemy.orm import relationship
+
+from app.domain.models import Base
+
+
+class Recipient(Base):
+    __tbalename__ = 'recipients'
+
+    id = Column(Integer, primary_key=True, autoincrement=True)
+
+    patient_id = Column(Integer, ForeignKey('mailing_delivery_methods.id'), nullable=False)
+    mailing_id = Column(Integer, ForeignKey('mailing.id'), nullable=False)
+
+    patient = relationship('MailingDeliveryMethod', back_populates='mailing')
+    mailing = relationship('Mailing', back_populates='recipients')
diff --git a/api/app/domain/models/users.py b/api/app/domain/models/users.py
index f6ca4c7..050144f 100644
--- a/api/app/domain/models/users.py
+++ b/api/app/domain/models/users.py
@@ -20,3 +20,4 @@ class User(Base):
 
     lens_issues = relationship('LensIssue', back_populates='doctor')
     appointments = relationship('Appointment', back_populates='doctor')
+    mailing = relationship('Mailing', back_populates='user')