I fixed the header as follow:
{
"accept": "application/json;odata=verbose",
"content-type": "application/json;odata=verbose"
}
But now I get an error in the body when the flow is triggered. This is the body:
{
'properties': {
'To': ['myAccount@myCompany.com'],
'Body': '<b>Yo</b><br/>O boy!',
'Subject': 'E-mail using Flow via SharePoint'
}
}
This is the error for the body:
A node of type 'StartArray' was read from the JSON reader when trying to read a value of a property; however, a 'PrimitiveValue' or 'StartObject' node was expected.