Most providers do not accept simple php-mail (like Anonymousmailer@domain.com) because of span and viruses - and often reject unsafe email adresses
*** So You will have to make entries for smtp instead - and such smtp-servers have positive mailing lists
in the CMS under settings -> ckeditor is now a menupoint SKIN . You can always add more compatible skins in the ckeditor-skins- directory which well the be in the list.