diff --git a/bin/boot_server_in_docker b/bin/boot_server_in_docker
index bd039722..ed52cac0 100755
--- a/bin/boot_server_in_docker
+++ b/bin/boot_server_in_docker
@@ -32,6 +32,7 @@ if [[ "${APPLICATION_ROOT:-}" != "/" ]]; then
 fi
 
 export IS_GUNICORN="true"
+export PROCESS_WAITING_MESSAGES="true"
 
 # THIS MUST BE THE LAST COMMAND!
 exec poetry run gunicorn ${additional_args} --bind "0.0.0.0:$port" --workers=3 --timeout 90 --capture-output --access-logfile '-' --log-level debug wsgi:app
diff --git a/bin/run_server_locally b/bin/run_server_locally
index 1d9af679..63c273c1 100755
--- a/bin/run_server_locally
+++ b/bin/run_server_locally
@@ -22,5 +22,5 @@ export APPLICATION_ROOT="/"
 if [[ -n "${SPIFFWORKFLOW_BACKEND_LOAD_FIXTURE_DATA:-}" ]]; then
   ./bin/boot_server_in_docker
 else
-  FLASK_APP=src/spiffworkflow_backend poetry run flask run -p 7000
+  PROCESS_WAITING_MESSAGES="true" FLASK_APP=src/spiffworkflow_backend poetry run flask run -p 7000
 fi
diff --git a/migrations/versions/a5a93fe63899_.py b/migrations/versions/c7735c07773c_.py
similarity index 93%
rename from migrations/versions/a5a93fe63899_.py
rename to migrations/versions/c7735c07773c_.py
index 1f64e5c4..050b5032 100644
--- a/migrations/versions/a5a93fe63899_.py
+++ b/migrations/versions/c7735c07773c_.py
@@ -1,8 +1,8 @@
 """empty message
 
-Revision ID: a5a93fe63899
+Revision ID: c7735c07773c
 Revises: 
-Create Date: 2022-07-27 08:51:44.791339
+Create Date: 2022-08-01 14:22:21.009841
 
 """
 from alembic import op
@@ -10,7 +10,7 @@ import sqlalchemy as sa
 
 
 # revision identifiers, used by Alembic.
-revision = 'a5a93fe63899'
+revision = 'c7735c07773c'
 down_revision = None
 branch_labels = None
 depends_on = None
@@ -31,6 +31,12 @@ def upgrade():
     sa.Column('new_name_two', sa.String(length=255), nullable=True),
     sa.PrimaryKeyConstraint('id')
     )
+    op.create_table('message_model',
+    sa.Column('id', sa.Integer(), nullable=False),
+    sa.Column('name', sa.String(length=50), nullable=True),
+    sa.PrimaryKeyConstraint('id')
+    )
+    op.create_index(op.f('ix_message_model_name'), 'message_model', ['name'], unique=True)
     op.create_table('user',
     sa.Column('id', sa.Integer(), nullable=False),
     sa.Column('username', sa.String(length=50), nullable=False),
@@ -135,8 +141,9 @@ def upgrade():
     sa.Column('id', sa.Integer(), nullable=False),
     sa.Column('process_instance_id', sa.Integer(), nullable=False),
     sa.Column('bpmn_element_id', sa.String(length=50), nullable=False),
-    sa.Column('correlation_name', sa.String(length=50), nullable=False),
-    sa.Column('correlation_value', sa.String(length=50), nullable=False),
+    sa.Column('messsage_type', sa.Enum('send', 'receive', name='messagetypes'), nullable=False),
+    sa.Column('message_model', sa.Integer(), nullable=False),
+    sa.ForeignKeyConstraint(['message_model'], ['message_model.id'], ),
     sa.ForeignKeyConstraint(['process_instance_id'], ['process_instance.id'], ),
     sa.PrimaryKeyConstraint('id')
     )
@@ -195,6 +202,8 @@ def downgrade():
     op.drop_table('process_instance')
     op.drop_table('principal')
     op.drop_table('user')
+    op.drop_index(op.f('ix_message_model_name'), table_name='message_model')
+    op.drop_table('message_model')
     op.drop_table('group')
     op.drop_table('admin_session')
     # ### end Alembic commands ###
diff --git a/poetry.lock b/poetry.lock
index b5d60ac0..51e39662 100644
--- a/poetry.lock
+++ b/poetry.lock
@@ -43,6 +43,32 @@ python-versions = "*"
 [package.extras]
 dev = ["black", "coverage", "isort", "pre-commit", "pyenchant", "pylint"]
 
+[[package]]
+name = "apscheduler"
+version = "3.9.1"
+description = "In-process task scheduler with Cron-like capabilities"
+category = "main"
+optional = false
+python-versions = ">=2.7, !=3.0.*, !=3.1.*, !=3.2.*, !=3.3.*, !=3.4.*, <4"
+
+[package.dependencies]
+pytz = "*"
+six = ">=1.4.0"
+tzlocal = ">=2.0,<3.0.0 || >=4.0.0"
+
+[package.extras]
+asyncio = ["trollius"]
+doc = ["sphinx", "sphinx-rtd-theme"]
+gevent = ["gevent"]
+mongodb = ["pymongo (>=3.0)"]
+redis = ["redis (>=3.0)"]
+rethinkdb = ["rethinkdb (>=2.4.0)"]
+sqlalchemy = ["sqlalchemy (>=0.8)"]
+testing = ["pytest", "pytest-cov", "pytest-tornado5", "mock", "pytest-asyncio (<0.6)", "pytest-asyncio"]
+tornado = ["tornado (>=4.3)"]
+twisted = ["twisted"]
+zookeeper = ["kazoo"]
+
 [[package]]
 name = "astroid"
 version = "2.11.6"
@@ -2093,7 +2119,7 @@ testing = ["pytest (>=6)", "pytest-checkdocs (>=2.4)", "pytest-flake8", "pytest-
 [metadata]
 lock-version = "1.1"
 python-versions = "^3.9"
-content-hash = "66503576ef158089a92526ed6982bc93481868a47fec14c47d1ce9a5bcc08979"
+content-hash = "37bb9f834037be053e37ca34ba825e2be692554e4c668a4bae42560987d6e092"
 
 [metadata.files]
 alabaster = [
@@ -2112,6 +2138,7 @@ aniso8601 = [
     {file = "aniso8601-9.0.1-py2.py3-none-any.whl", hash = "sha256:1d2b7ef82963909e93c4f24ce48d4de9e66009a21bf1c1e1c85bdd0812fe412f"},
     {file = "aniso8601-9.0.1.tar.gz", hash = "sha256:72e3117667eedf66951bb2d93f4296a56b94b078a8a95905a052611fb3f1b973"},
 ]
+apscheduler = []
 astroid = [
     {file = "astroid-2.11.6-py3-none-any.whl", hash = "sha256:ba33a82a9a9c06a5ceed98180c5aab16e29c285b828d94696bf32d6015ea82a9"},
     {file = "astroid-2.11.6.tar.gz", hash = "sha256:4f933d0bf5e408b03a6feb5d23793740c27e07340605f236496cd6ce552043d6"},
diff --git a/pyproject.toml b/pyproject.toml
index 6cc94f6d..8342be7a 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -47,6 +47,7 @@ PyJWT = "^2.4.0"
 gunicorn = "^20.1.0"
 types-pytz = "^2022.1.1"
 python-keycloak = "^1.9.1"
+APScheduler = "^3.9.1"
 
 
 [tool.poetry.dev-dependencies]
diff --git a/src/spiffworkflow_backend/__init__.py b/src/spiffworkflow_backend/__init__.py
index 45e4a066..a61c3084 100644
--- a/src/spiffworkflow_backend/__init__.py
+++ b/src/spiffworkflow_backend/__init__.py
@@ -5,6 +5,7 @@ from typing import Any
 import connexion  # type: ignore
 import flask.app
 import flask.json
+from apscheduler.schedulers.background import BackgroundScheduler
 from flask_bpmn.api.api_error import api_error_blueprint
 from flask_bpmn.models.db import db
 from flask_bpmn.models.db import migrate
@@ -16,6 +17,7 @@ from spiffworkflow_backend.config import setup_config
 from spiffworkflow_backend.routes.admin_blueprint.admin_blueprint import admin_blueprint
 from spiffworkflow_backend.routes.process_api_blueprint import process_api_blueprint
 from spiffworkflow_backend.routes.user_blueprint import user_blueprint
+from spiffworkflow_backend.services.message_service import MessageServiceWithAppContext
 
 
 class MyJSONEncoder(flask.json.JSONEncoder):
@@ -28,6 +30,12 @@ class MyJSONEncoder(flask.json.JSONEncoder):
         return super().default(obj)
 
 
+# def process_queued_messages(app: flask.app.Flask):
+#     """Process_queued_messages."""
+#     with app.app_context():
+#         MessageService().process_queued_messages()
+
+
 def create_app() -> flask.app.Flask:
     """Create_app."""
     # We need to create the sqlite database in a known location.
@@ -71,4 +79,13 @@ def create_app() -> flask.app.Flask:
 
     app.json_encoder = MyJSONEncoder
 
+    if app.config["PROCESS_WAITING_MESSAGES"]:
+        scheduler = BackgroundScheduler()
+        scheduler.add_job(
+            MessageServiceWithAppContext(app).process_queued_messages_with_app_context,
+            "interval",
+            minutes=1,
+        )
+        scheduler.start()
+
     return app  # type: ignore
diff --git a/src/spiffworkflow_backend/config/default.py b/src/spiffworkflow_backend/config/default.py
index 89f3aa72..c944baa9 100644
--- a/src/spiffworkflow_backend/config/default.py
+++ b/src/spiffworkflow_backend/config/default.py
@@ -7,3 +7,7 @@ CORS_DEFAULT = "*"
 CORS_ALLOW_ORIGINS = re.split(
     r",\s*", environ.get("CORS_ALLOW_ORIGINS", default=CORS_DEFAULT)
 )
+
+PROCESS_WAITING_MESSAGES = (
+    environ.get("PROCESS_WAITING_MESSAGES", default="false") == "true"
+)
diff --git a/src/spiffworkflow_backend/models/message_correlation.py b/src/spiffworkflow_backend/models/message_correlation.py
new file mode 100644
index 00000000..9bddeb1c
--- /dev/null
+++ b/src/spiffworkflow_backend/models/message_correlation.py
@@ -0,0 +1,25 @@
+"""Message_correlation."""
+from dataclasses import dataclass
+
+from flask_bpmn.models.db import db
+from flask_bpmn.models.db import SpiffworkflowBaseDBModel
+from sqlalchemy import ForeignKey
+
+from spiffworkflow_backend.models.message_instance import MessageInstanceModel
+
+
+@dataclass
+class MessageCorrelationModel(SpiffworkflowBaseDBModel):
+    """Message Correlations to relate queued messages together."""
+
+    __tablename__ = "message_correlation"
+    __table_args__ = (
+        db.UniqueConstraint(
+            "message_id", "name", name="message_id_name_unique"
+        ),
+    )
+
+    id = db.Column(db.Integer, primary_key=True)
+    message_id = db.Column(ForeignKey(MessageInstanceModel.id), nullable=False, index=True)
+    name = db.Column(db.String(50), nullable=False, index=True)
+    value = db.Column(db.String(50), nullable=False, index=True)
diff --git a/src/spiffworkflow_backend/models/queued_send_message.py b/src/spiffworkflow_backend/models/message_instance.py
similarity index 59%
rename from src/spiffworkflow_backend/models/queued_send_message.py
rename to src/spiffworkflow_backend/models/message_instance.py
index 13df3297..b4d10763 100644
--- a/src/spiffworkflow_backend/models/queued_send_message.py
+++ b/src/spiffworkflow_backend/models/message_instance.py
@@ -1,15 +1,25 @@
-"""Principal."""
+"""Message_instance."""
+import enum
+
 from dataclasses import dataclass
 
 from flask_bpmn.models.db import db
 from flask_bpmn.models.db import SpiffworkflowBaseDBModel
+from sqlalchemy import Enum
 from sqlalchemy import ForeignKey
 
 from spiffworkflow_backend.models.process_instance import ProcessInstanceModel
+from spiffworkflow_backend.models.message_model import MessageModel
+
+
+class MessageTypes(enum.Enum):
+    """MessageTypes."""
+    send = 1
+    receive = 2
 
 
 @dataclass
-class QueuedSendMessageModel(SpiffworkflowBaseDBModel):
+class MessageInstanceModel(SpiffworkflowBaseDBModel):
     """Messages from a process instance that are ready to send to a receiving task."""
 
     __tablename__ = "queued_send_message"
@@ -17,5 +27,5 @@ class QueuedSendMessageModel(SpiffworkflowBaseDBModel):
     id = db.Column(db.Integer, primary_key=True)
     process_instance_id = db.Column(ForeignKey(ProcessInstanceModel.id), nullable=False)  # type: ignore
     bpmn_element_id = db.Column(db.String(50), nullable=False)
-    correlation_name = db.Column(db.String(50), nullable=False)
-    correlation_value = db.Column(db.String(50), nullable=False)
+    messsage_type = db.Column(Enum(MessageTypes), nullable=False)
+    message_model = db.Column(ForeignKey(MessageModel.id), nullable=False)
diff --git a/src/spiffworkflow_backend/models/message_model.py b/src/spiffworkflow_backend/models/message_model.py
new file mode 100644
index 00000000..2780349e
--- /dev/null
+++ b/src/spiffworkflow_backend/models/message_model.py
@@ -0,0 +1,13 @@
+"""Message_model."""
+
+from flask_bpmn.models.db import db
+from flask_bpmn.models.db import SpiffworkflowBaseDBModel
+
+
+class MessageModel(SpiffworkflowBaseDBModel):
+    """MessageModel."""
+
+    __tablename__ = "message_model"
+
+    id = db.Column(db.Integer, primary_key=True)
+    name = db.Column(db.String(50), unique=True, index=True)
diff --git a/src/spiffworkflow_backend/models/queued_receive_message.py b/src/spiffworkflow_backend/models/queued_receive_message.py
deleted file mode 100644
index cfbd3bf1..00000000
--- a/src/spiffworkflow_backend/models/queued_receive_message.py
+++ /dev/null
@@ -1,21 +0,0 @@
-"""Principal."""
-from dataclasses import dataclass
-
-from flask_bpmn.models.db import db
-from flask_bpmn.models.db import SpiffworkflowBaseDBModel
-from sqlalchemy import ForeignKey
-
-from spiffworkflow_backend.models.process_instance import ProcessInstanceModel
-
-
-@dataclass
-class QueuedReceiveMessageModel(SpiffworkflowBaseDBModel):
-    """Messages from a process instance that are ready to receive a message from a task."""
-
-    __tablename__ = "queued_receive_message"
-
-    id = db.Column(db.Integer, primary_key=True)
-    process_instance_id = db.Column(ForeignKey(ProcessInstanceModel.id), nullable=False)  # type: ignore
-    bpmn_element_id = db.Column(db.String(50), nullable=False)
-    correlation_name = db.Column(db.String(50), nullable=False)
-    correlation_value = db.Column(db.String(50), nullable=False)
diff --git a/src/spiffworkflow_backend/services/message_service.py b/src/spiffworkflow_backend/services/message_service.py
new file mode 100644
index 00000000..1e626428
--- /dev/null
+++ b/src/spiffworkflow_backend/services/message_service.py
@@ -0,0 +1,32 @@
+"""Message_service."""
+
+import flask
+from spiffworkflow_backend.models.user import UserModel
+
+
+class MessageServiceWithAppContext:
+    """Wrapper for Message Service.
+
+    This wrappers is to facilitate running the MessageService from the scheduler
+    since we need to specify the app context then.
+    """
+
+    def __init__(self, app: flask.app.Flask):
+        """__init__."""
+        self.app = app
+
+    def process_queued_messages_with_app_context(self):
+        """Since this runs in a scheduler, we need to specify the app context as well."""
+        with self.app.app_context():
+            MessageService().process_queued_messages()
+
+
+class MessageService:
+    """MessageService."""
+
+    def process_queued_messages(self):
+        """Process_queued_messages."""
+        user = UserModel.query.first()
+        print(f"user: {user}")
+        # MessageInstanceModel.query
+        # if
diff --git a/src/spiffworkflow_backend/services/process_instance_processor.py b/src/spiffworkflow_backend/services/process_instance_processor.py
index 8bcb5dbb..45edca16 100644
--- a/src/spiffworkflow_backend/services/process_instance_processor.py
+++ b/src/spiffworkflow_backend/services/process_instance_processor.py
@@ -35,13 +35,12 @@ from SpiffWorkflow.util.deep_merge import DeepMerge  # type: ignore
 from spiffworkflow_backend.models.active_task import ActiveTaskModel
 from spiffworkflow_backend.models.file import File
 from spiffworkflow_backend.models.file import FileType
+from spiffworkflow_backend.models.message_instance import MessageInstanceModel
+from spiffworkflow_backend.models.message_instance import MessageModel
 from spiffworkflow_backend.models.principal import PrincipalModel
 from spiffworkflow_backend.models.process_instance import ProcessInstanceModel
 from spiffworkflow_backend.models.process_instance import ProcessInstanceStatus
 from spiffworkflow_backend.models.process_model import ProcessModelInfo
-from spiffworkflow_backend.models.queued_receive_message import (
-    QueuedReceiveMessageModel,
-)
 from spiffworkflow_backend.models.task_event import TaskAction
 from spiffworkflow_backend.models.task_event import TaskEventModel
 from spiffworkflow_backend.models.user import UserModelSchema
@@ -450,34 +449,48 @@ class ProcessInstanceProcessor:
         """Process_bpmn_events."""
         if self.bpmn_process_instance.bpmn_events:
             for bpmn_event in self.bpmn_process_instance.bpmn_events:
-                # FIXME: pseudocode - not sure how to determine message types yet
-                if bpmn_event.event == "ReceivedEvent":
-                    queued_message = QueuedReceiveMessageModel(
-                        process_instance_id=self.process_instance_model.id,
-                        bpmn_element_id=bpmn_event.task_name,
+                message_type = None
+
+                # TODO: message: who knows the of the message model?
+                # will it be in the bpmn_event?
+                message_model = MessageModel.query.filter_by(
+                    name=bpmn_event.message_name
+                )
+
+                if message_model is None:
+                    raise ApiError(
+                        "invalid_message_name",
+                        f"Invalid message name: {bpmn_event.message_name}.",
                     )
-                    db.session.add(queued_message)
-                    db.session.commit()
+
+                # TODO: message - not sure how to determine message types yet
+                if bpmn_event.event == "WaitEvent":  # and waiting for message:
+                    message_type = "receive"
                 elif bpmn_event.event == "SendEvent":
-                    queued_receive_message = (
-                        QueuedReceiveMessageModel.query.filter_by().first()
+                    message_type = "send"
+
+                if message_type is None:
+                    raise ApiError(
+                        "invalid_event_type",
+                        f"Invalid event type for a message: {bpmn_event.event}.",
                     )
-                    if queued_receive_message:
-                        process_instance = ProcessInstanceModel.query.filter_by(
-                            process_instance_id=queued_receive_message.process_instance_id
-                        ).first()
-                        if process_instance is None:
-                            raise ApiError(
-                                "process_instance_not_found",
-                                f"The process instance - {queued_receive_message.process_instance_id} - for receiving event - {queued_receive_message.id} - cannot be found",
-                            )
+
+                queued_message = MessageInstanceModel(
+                    process_instance_id=self.process_instance_model.id,
+                    bpmn_element_id=bpmn_event.task_name,
+                    message_type=message_type,
+                    message_model_id=message_model.id,
+                )
+                db.session.add(queued_message)
+                db.session.commit()
 
     def do_engine_steps(self, exit_at: None = None) -> None:
         """Do_engine_steps."""
         try:
             self.bpmn_process_instance.refresh_waiting_tasks()
             self.bpmn_process_instance.do_engine_steps(exit_at=exit_at)
-            self.process_bpmn_events()
+            # TODO: run this
+            # self.process_bpmn_events()
 
         except WorkflowTaskExecException as we:
             raise ApiError.from_workflow_exception("task_error", str(we), we) from we
diff --git a/tests/spiffworkflow_backend/helpers/test_data.py b/tests/spiffworkflow_backend/helpers/test_data.py
index 9afee257..3f8600e2 100644
--- a/tests/spiffworkflow_backend/helpers/test_data.py
+++ b/tests/spiffworkflow_backend/helpers/test_data.py
@@ -1,13 +1,18 @@
 """User."""
+import json
+from time import time
 from typing import Dict
 from typing import Optional
 
+from flask_bpmn.models.db import db
 from tests.spiffworkflow_backend.helpers.example_data import ExampleDataLoader
 
 from spiffworkflow_backend.exceptions.process_entity_not_found_error import (
     ProcessEntityNotFoundError,
 )
+from spiffworkflow_backend.helpers.fixture_data import find_or_create_user
 from spiffworkflow_backend.models.process_group import ProcessGroup
+from spiffworkflow_backend.models.process_instance import ProcessInstanceModel
 from spiffworkflow_backend.models.process_model import ProcessModelInfo
 from spiffworkflow_backend.models.user import UserModel
 from spiffworkflow_backend.services.process_model_service import ProcessModelService
@@ -68,6 +73,27 @@ def load_test_spec(
         return spec
 
 
+def create_process_instance_from_process_model(
+    process_model: ProcessModelInfo, status: str
+):
+    """Create_process_instance_from_process_model."""
+    user = find_or_create_user()
+    current_time = round(time.time())
+    process_instance = ProcessInstanceModel(
+        status=status,
+        process_initiator=user,
+        process_model_identifier=process_model.id,
+        process_group_identifier=process_model.process_group_id,
+        updated_at_in_seconds=round(time.time()),
+        start_in_seconds=current_time - (3600 * 1),
+        end_in_seconds=current_time - (3600 * 1 - 20),
+        bpmn_json=json.dumps({"ikey": "ivalue"}),
+    )
+    db.session.add(process_instance)
+    db.session.commit()
+    return process_instance
+
+
 # def user_info_to_query_string(user_info, redirect_url):
 #     query_string_list = []
 #     items = user_info.items()
diff --git a/tests/spiffworkflow_backend/unit/test_message_service.py b/tests/spiffworkflow_backend/unit/test_message_service.py
new file mode 100644
index 00000000..bbe10c18
--- /dev/null
+++ b/tests/spiffworkflow_backend/unit/test_message_service.py
@@ -0,0 +1,18 @@
+"""test_message_service."""
+from spiffworkflow_backend.services.message_model import MessageModel
+from spiffworkflow_backend.services.message_instance import MessageInstanceModel
+from tests.spiffworkflow_backend.helpers.test_data import create_process_instance_from_process_model
+
+
+def test_can_send_message_to_waiting_message() -> None:
+    """Test_can_send_message_to_waiting_message."""
+    message_model_name = "message_model_one"
+    message_model = MessageModel(name=message_model_name)
+    process_instance = create_process_instance_from_process_model
+
+    queued_message_send = MessageInstanceModel(
+        process_instance_id=process_instance.id,
+        bpmn_element_id="something",
+        message_type="send",
+        message_model=message_model,
+    )