I did that and it throws the error. Maybe my HTML is of the wrong version? Here's my code:
{
'properties': {
'__metadata': {
'type': 'SP.Utilities.EmailProperties'
},
'To': {
'results': ['SP_Group_DEV', 'SP Group_DEV2']
},
'Body': '
<p><span
style='font-size:10.0pt;line-height:115%;font-family:"Arial",sans-serif;
color:black'>The most recent list of special requests in which your
distributors have made Out-of-APR sales considered In-APR is now available on
the NA Channel Management SharePoint site. The Territory Sales Manager
needs to validate the request and edit the appropriate columns in the file.</span></p>
<p><b><span
style='font-size:10.0pt;line-height:115%;font-family:"Arial",sans-serif;
color:black'>For every request that affects your distributor you need to either
"Approve" or "Reject" each transaction in Column A of the
spreadsheet. Remember to add your name to Column B and the date in Column
C as well.</span></b></p>
<p><b><span
style='font-size:10.0pt;line-height:115%;font-family:"Arial",sans-serif;
color:red'>Please validate these in a timely manner, if you don't the
transaction will not be processed in SAP and could have an unintended result on
your distributor's CPM report. </span></b><span style='font-size:10.0pt;
line-height:115%;font-family:"Arial",sans-serif;color:black'>Once validated the
Territory Sales Manager should click "Save" in the top left. </span></p>
<p><span
style='font-size:10.0pt;line-height:115%;font-family:"Arial",sans-serif;
color:black'>If this list does not include any distributor requests for the
distributors you are responsible for, please disregard.</span></p>
<p><span
style='font-size:10.0pt;font-family:"Arial",sans-serif;color:black'>Please </span><a
href="https://link.com">
<span
style='font-size:10.0pt;font-family:"Arial",sans-serif;color:blue'>click here</span></a><span
style='font-size:10.0pt;font-family:"Arial",sans-serif;color:black'> to
see the list of requests.</span></p>
<p><span
style='font-size:10.0pt;line-height:115%;font-family:"Arial",sans-serif'>Thank
you,</span></p>
<p><span
style='font-size:10.0pt;font-family:"Arial",sans-serif'>Name</span></p>
<p>> </p>
</div>',
'Subject': 'Test email from MS Flow'
} }