Handle address bounces

[danielsuo]

Flash invalid address, move email to drafts? What about for basic?

{ data:
{ status: 422,
request:
{ 'Cache-Control': 'private',
'X-PM-ApiErrorCode': '406',
Date: 'Mon, 26 Mar 2018 14:47:18 GMT',
'Content-Length': '177',
'Content-Encoding': 'gzip',
'X-Powered-By': 'ASP.NET',
'Content-Type': 'application/json; charset=utf-8',
Server: 'unicorns-double-rainbow' },
response:
{ Message: 'You tried to send to a recipient that has been marked as inactive.\nFound inactive addresses: [email protected].\nInactive recipients are ones that have generated a hard bounce or a spam complaint. ',
ErrorCode: 406 } },