diff --git a/app/app/api/base.py b/app/app/api/base.py
index a792e8d..80f57b2 100644
--- a/app/app/api/base.py
+++ b/app/app/api/base.py
@@ -5,6 +5,7 @@ import arrow
 from flask import Blueprint, request, jsonify, g
 from flask_login import current_user
 
+from app import constants
 from app.db import Session
 from app.models import ApiKey
 
@@ -18,7 +19,9 @@ def authorize_request() -> Optional[Tuple[str, int]]:
     api_key = ApiKey.get_by(code=api_code)
 
     if not api_key:
-        if current_user.is_authenticated:
+        if current_user.is_authenticated and request.headers.get(
+            constants.HEADER_ALLOW_API_COOKIES
+        ):
             g.user = current_user
         else:
             return jsonify(error="Wrong api key"), 401
diff --git a/app/app/constants.py b/app/app/constants.py
new file mode 100644
index 0000000..b20bc6a
--- /dev/null
+++ b/app/app/constants.py
@@ -0,0 +1 @@
+HEADER_ALLOW_API_COOKIES = "X-Sl-Allowcookies"
diff --git a/app/app/mail_sender.py b/app/app/mail_sender.py
index 9610b45..9c74952 100644
--- a/app/app/mail_sender.py
+++ b/app/app/mail_sender.py
@@ -76,7 +76,6 @@ class SendRequest:
         file_path = os.path.join(config.SAVE_UNSENT_DIR, file_name)
         self.save_request_to_file(file_path)
 
-    @staticmethod
     def save_request_to_failed_dir(self, prefix: str = "DeliveryRetryFail"):
         file_name = (
             f"{prefix}-{int(time.time())}-{uuid.uuid4()}.{SendRequest.SAVE_EXTENSION}"
diff --git a/app/app/session.py b/app/app/session.py
index 481e5ff..93acd3b 100644
--- a/app/app/session.py
+++ b/app/app/session.py
@@ -87,6 +87,7 @@ class RedisSessionStore(SessionInterface):
         httponly = self.get_cookie_httponly(app)
         secure = self.get_cookie_secure(app)
         expires = self.get_expiration_time(app, session)
+        samesite = self.get_cookie_samesite(app)
         val = pickle.dumps(dict(session))
         ttl = int(app.permanent_session_lifetime.total_seconds())
         # Only 5 minutes for non-authenticated sessions.
@@ -109,6 +110,7 @@ class RedisSessionStore(SessionInterface):
             domain=domain,
             path=path,
             secure=secure,
+            samesite=samesite,
         )
 
 
diff --git a/app/email_handler.py b/app/email_handler.py
index 2882e56..7257800 100644
--- a/app/email_handler.py
+++ b/app/email_handler.py
@@ -235,13 +235,14 @@ def get_or_create_contact(from_header: str, mail_from: str, alias: Alias) -> Con
             contact.mail_from = mail_from
             Session.commit()
     else:
+        alias_id = alias.id
         try:
             contact_email_for_reply = (
                 contact_email if is_valid_email(contact_email) else ""
             )
             contact = Contact.create(
                 user_id=alias.user_id,
-                alias_id=alias.id,
+                alias_id=alias_id,
                 website_email=contact_email,
                 name=contact_name,
                 mail_from=mail_from,
@@ -261,9 +262,11 @@ def get_or_create_contact(from_header: str, mail_from: str, alias: Alias) -> Con
 
             Session.commit()
         except IntegrityError:
-            LOG.w(f"Contact with email {contact_email} for alias {alias} already exist")
-            Session.rollback()
-            contact = Contact.get_by(alias_id=alias.id, website_email=contact_email)
+            # No need to manually rollback, as IntegrityError already rolls back
+            LOG.info(
+                f"Contact with email {contact_email} for alias_id {alias_id} already existed, fetching from DB"
+            )
+            contact = Contact.get_by(alias_id=alias_id, website_email=contact_email)
 
     return contact
 
@@ -662,6 +665,9 @@ def handle_forward(envelope, msg: Message, rcpt_to: str) -> List[Tuple[bool, str
     from_header = get_header_unicode(msg[headers.FROM])
     LOG.d("Create or get contact for from_header:%s", from_header)
     contact = get_or_create_contact(from_header, envelope.mail_from, alias)
+    alias = (
+        contact.alias
+    )  # In case the Session was closed in the get_or_create we re-fetch the alias
 
     reply_to_contact = None
     if msg[headers.REPLY_TO]:
diff --git a/app/server.py b/app/server.py
index ecbe00a..04278dc 100644
--- a/app/server.py
+++ b/app/server.py
@@ -29,7 +29,7 @@ from sentry_sdk.integrations.flask import FlaskIntegration
 from sentry_sdk.integrations.sqlalchemy import SqlalchemyIntegration
 from werkzeug.middleware.proxy_fix import ProxyFix
 
-from app import paddle_utils, config, paddle_callback
+from app import paddle_utils, config, paddle_callback, constants
 from app.admin_model import (
     SLAdminIndexView,
     UserAdmin,
@@ -430,6 +430,7 @@ def jinja2_filter(app):
             PAGE_LIMIT=PAGE_LIMIT,
             ZENDESK_ENABLED=ZENDESK_ENABLED,
             MAX_NB_EMAIL_FREE_PLAN=MAX_NB_EMAIL_FREE_PLAN,
+            HEADER_ALLOW_API_COOKIES=constants.HEADER_ALLOW_API_COOKIES,
         )
 
 
@@ -702,7 +703,12 @@ def setup_coinbase_commerce(app):
 
 
 def handle_coinbase_event(event) -> bool:
-    user_id = int(event["data"]["metadata"]["user_id"])
+    server_user_id = event["data"]["metadata"]["user_id"]
+    try:
+        user_id = int(server_user_id)
+    except ValueError:
+        user_id = int(float(server_user_id))
+
     code = event["data"]["code"]
     user = User.get(user_id)
     if not user:
diff --git a/app/templates/dashboard/alias_contact_manager.html b/app/templates/dashboard/alias_contact_manager.html
index 886327a..1fdc518 100644
--- a/app/templates/dashboard/alias_contact_manager.html
+++ b/app/templates/dashboard/alias_contact_manager.html
@@ -264,6 +264,7 @@
           method: "POST",
           headers: {
             "Content-Type": "application/json",
+              '{{HEADER_ALLOW_API_COOKIES}}': 'allow'
           }
         });
 
diff --git a/app/templates/dashboard/support.html b/app/templates/dashboard/support.html
index 81b7a68..d51f697 100644
--- a/app/templates/dashboard/support.html
+++ b/app/templates/dashboard/support.html
@@ -80,7 +80,10 @@
       },
       methods: {
         generateRandomAlias: async function (event) {
-          let result = await fetch('/api/alias/random/new', {method: 'POST'});
+          let result = await fetch('/api/alias/random/new', {method: 'POST',
+              headers: {
+              '{{HEADER_ALLOW_API_COOKIES}}': 'allow'
+          }});
           if (result.ok) {
             let data = await result.json();
             this.ticket_email = data.alias;
diff --git a/app/templates/footer.html b/app/templates/footer.html
index 180b6c7..0aa7c33 100644
--- a/app/templates/footer.html
+++ b/app/templates/footer.html
@@ -216,6 +216,7 @@
           method: "POST",
           headers: {
             "Content-Type": "application/json",
+              '{{HEADER_ALLOW_API_COOKIES}}': 'allow'
           }
         });
 
@@ -232,6 +233,7 @@
           method: "GET",
           headers: {
             "Content-Type": "application/json",
+              '{{HEADER_ALLOW_API_COOKIES}}': 'allow'
           }
         });
         if (res.ok) {
@@ -249,6 +251,7 @@
         method: "GET",
         headers: {
           "Content-Type": "application/json",
+            '{{HEADER_ALLOW_API_COOKIES}}': 'allow'
         }
       });
       if (res.ok) {
diff --git a/app/templates/phone/phone_reservation.html b/app/templates/phone/phone_reservation.html
index c1bb8b8..cf1ec3e 100644
--- a/app/templates/phone/phone_reservation.html
+++ b/app/templates/phone/phone_reservation.html
@@ -87,6 +87,7 @@
             method: "GET",
             headers: {
               "Content-Type": "application/json",
+                '{{HEADER_ALLOW_API_COOKIES}}': 'allow'
             }
           });
           if (res.ok) {
diff --git a/app/tests/conftest.py b/app/tests/conftest.py
index 37b2abb..43ea7ac 100644
--- a/app/tests/conftest.py
+++ b/app/tests/conftest.py
@@ -1,5 +1,7 @@
 import os
 
+from flask import testing
+
 # use the tests/test.env config fle
 # flake8: noqa: E402
 
@@ -42,7 +44,16 @@ def flask_app():
     yield app
 
 
-from app import config
+from app import config, constants
+
+
+class CustomTestClient(testing.FlaskClient):
+    def open(self, *args, **kwargs):
+        if isinstance(args[0], str):
+            headers = kwargs.pop("headers", {})
+            headers.update({constants.HEADER_ALLOW_API_COOKIES: "allow"})
+            kwargs["headers"] = headers
+        return super().open(*args, **kwargs)
 
 
 @pytest.fixture
@@ -53,7 +64,9 @@ def flask_client():
         # disable rate limit during test
         config.DISABLE_RATE_LIMIT = True
         try:
+            app.test_client_class = CustomTestClient
             client = app.test_client()
+            client.environ_base[constants.HEADER_ALLOW_API_COOKIES] = "allow"
             yield client
         finally:
             # disable rate limit again as some tests might enable rate limit