Using Set-ReceiveConnector -Bindings “${IPAddr}:25″ should work for a single IP; you need to use this syntax with the additional accolades, as the colon is used in PowerShell to associate a variable with a scope.
Alternatively, which also can deal with multiple returned addresses, use something like:
Set-ReceiveConnector -Bindings ($IPAddr | ForEach { $_+”:25″ })
Hope this helps.
