Here is the diagnostic result:
OS: Linux cl7-web3.ispfr.net 3.2.45+nuxit-squeeze-grsec #1 SMP Tue May 21 09:18:11 UTC 2013 x86_64
HTTP User Agent: Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/45.0.2454.101 Safari/537.36
PHP: Linux 5.2.17 C
PHP Dependencies: iconv=Yes, spl_autoload=Yes, openssl=Yes, sockets=No, allow_url_fopen=Yes, mcrypt=Yes
WordPress: 4.3.1 fr_FR
WordPress Theme: OrelPhone
WordPress Plugins: All in one Favicon, All In One SEO Pack, Contact Form 7, Easy Excerpt, jQuery Lightbox, News-Ticker, NextGEN Gallery by Photocrati, Postman SMTP, Really Simple CAPTCHA, Remove Author Pages, Simple Google Sitemap XML, Wordfence Security
WordPress wp_mail Filter(s): wp_staticize_emoji_for_email
Postman: 1.6.24
Postman Sender Domain (Envelope|Message): orelphone.com | orelphone.com
Postman Prevent Message Sender Override (Email|Name): No | No
Postman Transport URI: smtp:none:plain://smtp.numero899.com:25
Postman Transport Status (Configured|Ready|Connected): Yes | Yes | Yes
Postman Deliveries (Success|Fail): 0 | 1
Your mail server is telling you that it wants authentication – that means sending it an account username and a password.
smtp:none:plain://smtp.numero899.com:25
But you don’t have authentication enabled. You could trying using the Wizard to setup Postman if you’re not sure what the email settings mean.
