• New mailing library with new api sending methods and webhook endpoints for Mandrill, Postmark, Mailjet, Mailersend, Brevo.
• Sending domains to be used for DKIM-signing. DKIM-signing is now a built-in feature. See the docs.
• Sidebar widget for the news log along with an extensive redesign. You can read more and experience the widget here. Practically, it became an app on its own similar to those offered by Headway and Beamer (but without the monthly fee).
• A new type of opt-out link that suppresses the subscriber but keeps all history.
• Load, update or add a subscriber directly from your CRM/CMS.
• New methods and options were added to the API related to retrieving statistics, creating campaigns and creating/updating subscribers.
• Numerous improvements and productivity enhancements. There is seriously a lot more to read here.
• See the new demo.

When you land on Mail tester you will see an one-time, temporary email address to copy.

There are two ways to proceed. 

• Copy this email address, open an html newsletter and send a single test email to this address.
• Or better, add this email address to your test list and send a campaign to your list.
• Then return to Mail tester and click to check your score.

Gmail will stop accepting your emails if they are not DKIM-signed or without an SPF record. Here is a detailed article on this issue from Spamresource.com.

What you should do

• Check your emails for DKIM and SPF records.
• Check your nuevoMailer activity log for errors.
• Check your email clients report. If you had seen a drop in Gmail then something may be wrong.
• Use Google's postmaster tools.
• With nuevoMailer SB v.9.9 and ESP v.4 you can DKIM-sign your emails. You should only do this if your provider does not give you this option. You can read more on this here.