FYI – After upgrading from v1.0.8 to v1.0.9 in the WordPress dashboard I couldn’t log in to wp-admin getting only a blank screen because the Sucuri plugin automatically sends login email notices.
My fix was to fire up FileZilla (or use your favorite FTP client) and rename the plugin directory to _easy-wp-smtp (note the leading underscore _) to disable the plugin.
I was then able to login to wp-admin, delete the old plugin, install Easy WP SMTP v1.0.9 and re-enter the mail account settings. If you’re using Google Apps for Business see the Gmail SMTP server settings.
If you’re using 2-Step Verification with Gmail (and you should be!) you’ll need to regenerate an App Specific Password if you didn’t save the old app specific password. I don’t save app specific passwords offline security.