slack channel for large workspaces

[mraklay]

Hi there
Thanks for making this project open source!

I'm setting it up for the first time and encountered an error sending alerts to Slack. However, email alerts still work.
A little research revealed that the Slack method
conversations_list from slack.py

response = client.conversations_list(types="public_channel,private_channel")
channels = response["channels"]

doesn't return all available channels from my workspace, but rather a limited list. My workspace has over 100 channels, so I was getting an error.
Channel not found

Explicitly adding a limit helped:

channels = []
cursor = None
while True:
    response = client.conversations_list(
        types="public_channel,private_channel",
        limit=1000,
        cursor=cursor
    )
    channels.extend(response["channels"])
    cursor = response.get("response_metadata", {}).get("next_cursor")
    if not cursor:
        break