plugin WP
http://www.webmarketing-com.com/2015/01/19/34783-11-plugins-wordpress-indispensables-installer-sur-votre-blog http://www.insidedaweb.com/wordpress-seo/plugins-wordpress/wordpress-top-100-plugins/
base email responsive (audrey)
guide css 2017 https://www.campaignmonitor.com/css/media-queries/media/
templates gratuits : https://www.codeur.com/blog/template-email-gratuit-html/
tailles ecrans : http://www.responsive-mind.fr/resolution-iphone-retina/