victor-torres: cc @ejulio 
victor-torres: Thank you for your suggestions, @rennerocha. I've just pushed a couple of commits that should have addressed them. Let me know if I can help with anything else.
diff --git a/spidermon/contrib/actions/slack/__init__.py b/spidermon/contrib/actions/slack/__init__.py
index 8674c0e..0de8dd4 100644
--- a/spidermon/contrib/actions/slack/__init__.py
+++ b/spidermon/contrib/actions/slack/__init__.py
@@ -194,7 +194,7 @@ class SendSlackMessage(ActionWithTemplates):
         return {
             "sender_token": crawler.settings.get("SPIDERMON_SLACK_SENDER_TOKEN"),
             "sender_name": crawler.settings.get("SPIDERMON_SLACK_SENDER_NAME"),
-            "recipients": crawler.settings.get("SPIDERMON_SLACK_RECIPIENTS"),
+            "recipients": crawler.settings.getlist("SPIDERMON_SLACK_RECIPIENTS"),
             "message": crawler.settings.get("SPIDERMON_SLACK_MESSAGE"),
             "message_template": crawler.settings.get(
                 "SPIDERMON_SLACK_MESSAGE_TEMPLATE"

It's not possible to specify SPIDERMON_SLACK_RECIPIENTS via Scrapy Cloud
We should replace `settings.get` by `settings.getlist`. I'm working on a pull request. 
diff --git a/tests/contrib/actions/slack/test_slack_message_manager.py b/tests/contrib/actions/slack/test_slack_message_manager.py
index 1035957..63ee934 100644
--- a/tests/contrib/actions/slack/test_slack_message_manager.py
+++ b/tests/contrib/actions/slack/test_slack_message_manager.py
@@ -1,5 +1,11 @@
 import pytest
-from spidermon.contrib.actions.slack import SlackMessageManager
+
+from scrapy.utils.test import get_crawler
+
+from spidermon.contrib.actions.slack import (
+    SlackMessageManager,
+    SendSlackMessage,
+)
 
 
 @pytest.fixture
@@ -39,3 +45,13 @@ def test_api_call_with_error_should_log_error_msg(mocker, logger_error):
 
     assert logger_error.call_count == 1
     assert error_msg in logger_error.call_args_list[0][0]
+
+
+@pytest.mark.parametrize("recipients", ["foo,bar", ["foo", "bar"]])
+def test_load_recipients_list_from_crawler_settings(recipients):
+    settings = {
+        "SPIDERMON_SLACK_RECIPIENTS": recipients,
+    }
+    crawler = get_crawler(settings_dict=settings)
+    kwargs = SendSlackMessage.from_crawler_kwargs(crawler)
+    assert kwargs["recipients"] == ["foo", "bar"]

pip install -e .[monitoring,validation]
parse_log_pytest
requirements.txt
pytest pytest-cov
apt-get update apt-get install -y gcc
3.7
requirements.txt
pytest --no-header -rA --tb=line --color=no -p no:cacheprovider -W ignore::DeprecationWarning
arrow==1.2.3
attrs==24.2.0
Automat==22.10.0
black==23.3.0
boto==2.49.0
cached-property==1.5.2
cachetools==5.5.2
certifi @ file:///croot/certifi_1671487769961/work/certifi
cffi==1.15.1
chardet==5.2.0
charset-normalizer==3.4.1
click==8.1.8
colorama==0.4.6
constantly==15.1.0
coverage==7.2.7
cryptography==44.0.2
cssselect==1.2.0
cssutils==2.7.1
distlib==0.3.9
exceptiongroup==1.2.2
filelock==3.12.2
fqdn==1.5.1
hyperlink==21.0.0
idna==3.10
importlib-metadata==6.7.0
importlib-resources==5.12.0
incremental==22.10.0
iniconfig==2.0.0
isoduration==20.11.0
itemadapter==0.8.0
itemloaders==1.1.0
Jinja2==3.1.6
jmespath==1.0.1
jsonpointer==3.0.0
jsonschema==4.17.3
lxml==5.3.1
MarkupSafe==2.1.5
mypy-extensions==1.0.0
packaging==24.0
parsel==1.8.1
pathspec==0.11.2
pkgutil_resolve_name==1.3.10
platformdirs==4.0.0
pluggy==1.2.0
premailer==3.10.0
Protego==0.3.0
pyasn1==0.5.1
pyasn1-modules==0.3.0
pycparser==2.21
PyDispatcher==2.0.7
pyOpenSSL==25.0.0
pyproject-api==1.5.3
pyrsistent==0.19.3
pytest==7.4.4
pytest-cov==4.1.0
pytest-mock==3.11.1
python-dateutil==2.9.0.post0
python-slugify==8.0.4
queuelib==1.6.2
requests==2.31.0
requests-file==2.1.0
rfc3339-validator==0.1.4
rfc3987==1.3.8
schematics==2.1.1
Scrapy==2.9.0
sentry-sdk==2.24.1
service-identity==21.1.0
six==1.17.0
slackclient==1.3.2
-e git+https://github.com/scrapinghub/spidermon.git@deecd7527971a1dfd3aa646de88acbc81696da81#egg=spidermon
text-unidecode==1.3
tldextract==4.0.0
tomli==2.0.1
tox==4.8.0
Twisted==23.8.0
typed-ast==1.5.5
typing_extensions==4.7.1
uri-template==1.3.0
urllib3==2.0.7
virtualenv==20.26.6
w3lib==2.1.2
webcolors==1.13
websocket-client==0.54.0
zipp==3.15.0
zope.interface==6.4.post2

name: spidermon
channels:
  - defaults
  - https://repo.anaconda.com/pkgs/main
  - https://repo.anaconda.com/pkgs/r
  - conda-forge
dependencies:
  - _libgcc_mutex=0.1=main
  - _openmp_mutex=5.1=1_gnu
  - ca-certificates=2025.2.25=h06a4308_0
  - certifi=2022.12.7=py37h06a4308_0
  - ld_impl_linux-64=2.40=h12ee557_0
  - libffi=3.4.4=h6a678d5_1
  - libgcc-ng=11.2.0=h1234567_1
  - libgomp=11.2.0=h1234567_1
  - libstdcxx-ng=11.2.0=h1234567_1
  - ncurses=6.4=h6a678d5_0
  - openssl=1.1.1w=h7f8727e_0
  - pip=22.3.1=py37h06a4308_0
  - python=3.7.16=h7a1cb2a_0
  - readline=8.2=h5eee18b_0
  - setuptools=65.6.3=py37h06a4308_0
  - sqlite=3.45.3=h5eee18b_0
  - tk=8.6.14=h39e8969_0
  - wheel=0.38.4=py37h06a4308_0
  - xz=5.6.4=h5eee18b_1
  - zlib=1.2.13=h5eee18b_1
  - pip:
      - arrow==1.2.3
      - attrs==24.2.0
      - automat==22.10.0
      - black==23.3.0
      - boto==2.49.0
      - cached-property==1.5.2
      - cachetools==5.5.2
      - cffi==1.15.1
      - chardet==5.2.0
      - charset-normalizer==3.4.1
      - click==8.1.8
      - colorama==0.4.6
      - constantly==15.1.0
      - coverage==7.2.7
      - cryptography==44.0.2
      - cssselect==1.2.0
      - cssutils==2.7.1
      - distlib==0.3.9
      - exceptiongroup==1.2.2
      - filelock==3.12.2
      - fqdn==1.5.1
      - hyperlink==21.0.0
      - idna==3.10
      - importlib-metadata==6.7.0
      - importlib-resources==5.12.0
      - incremental==22.10.0
      - iniconfig==2.0.0
      - isoduration==20.11.0
      - itemadapter==0.8.0
      - itemloaders==1.1.0
      - jinja2==3.1.6
      - jmespath==1.0.1
      - jsonpointer==3.0.0
      - jsonschema==4.17.3
      - lxml==5.3.1
      - markupsafe==2.1.5
      - mypy-extensions==1.0.0
      - packaging==24.0
      - parsel==1.8.1
      - pathspec==0.11.2
      - pkgutil-resolve-name==1.3.10
      - platformdirs==4.0.0
      - pluggy==1.2.0
      - premailer==3.10.0
      - protego==0.3.0
      - pyasn1==0.5.1
      - pyasn1-modules==0.3.0
      - pycparser==2.21
      - pydispatcher==2.0.7
      - pyopenssl==25.0.0
      - pyproject-api==1.5.3
      - pyrsistent==0.19.3
      - pytest==7.4.4
      - pytest-cov==4.1.0
      - pytest-mock==3.11.1
      - python-dateutil==2.9.0.post0
      - python-slugify==8.0.4
      - queuelib==1.6.2
      - requests==2.31.0
      - requests-file==2.1.0
      - rfc3339-validator==0.1.4
      - rfc3987==1.3.8
      - schematics==2.1.1
      - scrapy==2.9.0
      - sentry-sdk==2.24.1
      - service-identity==21.1.0
      - six==1.17.0
      - slackclient==1.3.2
      - text-unidecode==1.3
      - tldextract==4.0.0
      - tomli==2.0.1
      - tox==4.8.0
      - twisted==23.8.0
      - typed-ast==1.5.5
      - typing-extensions==4.7.1
      - uri-template==1.3.0
      - urllib3==2.0.7
      - virtualenv==20.26.6
      - w3lib==2.1.2
      - webcolors==1.13
      - websocket-client==0.54.0
      - zipp==3.15.0
      - zope-interface==6.4.post2
prefix: /opt/conda/envs/spidermon

tests/contrib/actions/slack/test_slack_message_manager.py::test_load_recipients_list_from_crawler_settings[foo,bar]
tests/contrib/actions/slack/test_slack_message_manager.py::test_api_call_with_no_error_should_not_log_messages tests/contrib/actions/slack/test_slack_message_manager.py::test_api_call_with_error_should_log_error_msg tests/contrib/actions/slack/test_slack_message_manager.py::test_load_recipients_list_from_crawler_settings[recipients1]
spidermon/contrib/actions/slack/__init__.py
spidermon/contrib/actions/slack/__init__.py