Always good to update the team about ongoing releases.
By using the Slack API in a VSTS PowerShell Release Task it is easy to update your team members.
To post messsage to Slack from VSTS I used the VSTS Powershell task with a function to post messages. For the PowerShell function I re-used the implementation from http://wahlnetwork.com/2015/08/17/using-powershell-to-post-slack-messages/ (thx), tuned it a bit with Release specific parameters and all that is left is adding a VSTS PowerShell Release Task which calls the PowerShell method. Too easy…
It should be even easier when there is a custom taks for VSTS to post messages, or a Zapier action, or a Service Hook in Slack https://www.visualstudio.com/en-us/get-started/integrate/service-hooks/slack-and-vso-vs. But for now this simply works.