Small text improvements for PR mconf#86

config/locales/en/_mailer.yml

@@ -93,9 +93,9 @@ en:
         password: "Access key"
         start: "Start"
         subject: "Subject"
-        quality_warn: "To ensure the quality of your experience it is indispensable to use a headset to participate in the web conference and use Google Chrome or Mozilla Firefox browser. Do not use notebook's built in microphone and webcam neither Internet Explorer browser."
+        quality_warn: "To ensure a good quality of experience it is indispensable to use a headset and to use the browsers Google Chrome or Mozilla Firefox to participate in the web conference. Do not use your notebook's built in microphone and webcam and don't use the browser Internet Explorer."
         user_manual: "The user manual and system requirements for using the service are available in the link https://wiki.rnp.br/x/oW5jBQ."
-        rnp_contact: "In case of doubt or problems refer to the RNP Service Desk by the phone number 0800 722 0216, by whatsapp (61) 9 9960 5971 or by e-mail sd@rnp.br."
+        rnp_contact: "In case of doubt or problems contact RNP's Service Desk at the phone number 0800 722 0216, whatsapp (61) 9 9960 5971 or email sd@rnp.br."
       subject: "Web conference invitation"
   shared:
     invitation_email: