Yesterday, March 31, a number of our customers experienced warnings in Google Chrome and bounced emails regarding message content. Our team promptly began an investigation.
We identified a customer who sent an email with a link to a phishing site. Despite the protections we put in place, some other legitimate Nutshell links were caught up in the crossfire, and falsely labeled as unsafe by Google.
This caused some emails sent from Nutshell with click and open tracking to be rejected as spam or to display a warning message to recipients. Our engineers put a fix in place to address this as of Thursday evening, March 31, around 6pm ET. These warnings will no longer appear for new emails sent from Nutshell.
We are sincerely sorry for the trouble and our team is working hard to ensure this does not happen again. Security is a top priority for Nutshell and we are doubling down on our efforts to prevent malicious behavior using Nutshell email, as well as to isolate these effects to protect your email sending reputation.
If you have any questions regarding email delivery, please contact our team!