Sending emails failing after few(undefined) successful attempts

Sending emails fails from time to time and it keeps failing for about a minute.

Seen on:

• Staging env with bug fixed chrome extension

• Production with prod chrome extension

• Boris env with latest Chrome master

Debug info from Chrome extension failier (not sure if relevant) :

[ERROR:signEmail(passport, sender, emailBody)] Error while trying to sign email :+1 \"{\\\"error\\\":\\\"{\\\\\\\"stack\\\\\\\":\\\\\\\"SyntaxError: Unexpected token u in JSON at position 0\\\\\\\\n    at JSON.parse (<anonymous>)\\\\\\\\n    at r.set (https://staging.vereign.com/vcl/js/iframe:8:622788)\\\\\\\\n    at https://staging.vereign.com/vcl/js/iframe:8:751539\\\\\\\\n    at new Promise (<anonymous>)\\\\\\\\n    at j (https://staging.vereign.com/vcl/js/iframe:8:751386)\\\\\\\\n    at Object.<anonymous> (https://staging.vereign.com/vcl/js/iframe:8:761655)\\\\\\\\n    at S (https://staging.vereign.com/vcl/js/iframe:8:743371)\\\\\\\\n    at Generator._invoke (https://staging.vereign.com/vcl/js/iframe:8:743159)\\\\\\\\n    at Generator.e.(anonymous function) [as next] (https://staging.vereign.com/vcl/js/iframe:8:743550)\\\\\\\\n    at u (https://staging.vereign.com/vcl/js/iframe:8:746340)\\\\\\\",\\\\\\\"name\\\\\\\":\\\\\\\"SyntaxError\\\\\\\",\\\\\\\"message\\\\\\\":\\\\\\\"Unexpected token u in JSON at position 0\\\\\\\"}\\\"}\" \n","Tue Feb 26 2019 13:02:42 GMT+0200 (Eastern European Standard Time)][VEREIGN INFO]>> [ERROR] -> sendComposedMessage :+1 \"{\\\"error\\\":{\\\"name\\\":\\\"SyntaxError\\\",\\\"message\\\":\\\"Unexpected token u in JSON at position 0\\\"}}\" \n","Tue Feb 26 2019 13:02:43 GMT+0200 (Eastern European Standard Time)][VEREIGN INFO]>> [EVENT] -> getAuthToken :+1 \"{}\" \n","Tue Feb 26 2019 13:02:43 GMT+0200 (Eastern European Standard Time)][VEREIGN INFO]>> [SUCCESS] -> getAuthToken :+1 \"{\\\"data\\\":\\\"ya29.Gly8BtTLGmeaEMlUjUhfeZ9WNQRkVadRs2Lm92v-k6IQtkADZzPQSSWvuwtUxmEI8DzzSDF8UeFTfLWivOqpII4ufk2Sh6hiNAQQeIRphSlJkHY0uDgTbYT9UibKiA\\\"}\" \n","Tue Feb 26 2019 13:02:43 GMT+0200 (Eastern European Standard Time)][VEREIGN INFO]>> [EVENT:vereign()] event.type: QRCodeUpdated :+1 \"{\\\"actionID\\\":\\\"dd53491f-9f87-495e-bc75-e26833226c49\\\",\\\"type\\\":\\\"QRCodeUpdated\\\",\\\"payloads\\\":[\\\"22375589\\\",\\\"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAKQAAACkCAYAAAAZtYVBAAAKlklEQVR4Xu3d0XIbMQ5EUfn/PzpbtU874yqd7QKojJ3OK0AQbFyCnJGsfP358+fPq/+qwEMU+CqQD6lE0/ivAgWyIDxKgQL5qHI0mQJZBh6lQIF8VDmaTIEsA49SoEA+qhxNpkCWgUcpUCAfVY4mUyDLwKMUKJCPKkeTKZBl4FEKFMhHlaPJFMgy8CgFCuSjytFkxkB+fX19VMXtr2/e81f81P8ujsan9nv8e/4/rT4F8rahCuSsv0g/RS+QBVKMRPYCGcn13VlHZHrkKh3Nl9p7ZN8UkIAqkOxPi687me5wsgsw6

Steps to reproduce:

1.Log into vereign

2.Log into chrome extension

3.Log into Gmail

4.Send verified email - message is displayed "Email has been sent!"

5.Send another verified email - Message is displayed "Can't send email!"

Expected - message to be displayed "Email has been sent!"

Actual - message displayed "Can't send email!"

Additional

When the issue is seen(meaning you cant send an email), and you logout/login on Vereign extension, then you will be able to send successfully few emails. And again after few successful attempts the issue occur again.