This error normally happens when your email password has changed since you initially synced with Lexicata, meaning our system can no longer access your email account to send the message. If this is not the case, then it is possible that the connection between the email account and our servers has expired and simply needs to be reconnected.
When this error occurs, the email will still be delivered, but it will be sent via a backup mail server called Mailgun instead of through your email account. Rest assured that all emails sent through Lexicata will still be delivered to their intended receivers.
To fix the problem, all you need to do is un-sync, and then re-sync your email. Here are the steps:
1) Go to Email Settings (https://lexicata.com/settings#email)
2) Click "un-sync email" at the top of the page
3) When the page reloads, click "Sync Email"
4) Input your correct credentials
This should prevent the error from happening moving forward 99% of the time, however, if the problem persists please reach out to us on the Live Chat or submit a request.