By default, when a new team is created in Microsoft Teams, this team is not visible in Outlook, even when the team has an underlying group. Additionally the team is not shown in the address list, when you want to add a recipient for an email. The reason for this is that the properties HiddenFromExchangeClientsEnabled and HiddenFromAddressListsEnabled are set to true, when the group for the team is created.

To make the team visible in Outlook we can use some PowerShell. First we need to connect to Exchange Online. Here is a simple script to do this connection:

if ($cred -eq $null)
$cred = Get-Credential
Write-Host "Connecting to Exchange Online"
$exchangeSession = New-PSSession ConfigurationName Microsoft.Exchange ConnectionUri Credential $cred Authentication Basic AllowRedirection
Import-PSSession $exchangeSession | Out-Null
Write-Host "Connected to Exchange Online"

When that is done, we just have one single line of code to run, to make the team visible in Outlook:

Set-UnifiedGroup -Identity MyTeam -HiddenFromExchangeClientsEnabled:$False

Now, you can discover the group for the team in Outlook/Outlook Online.