=====Envoi de mail automatique avec gmail=====
====E1. Installer le client smtp sSMTP====
 Par défaut, mail se sert d'exim, un autre system d'envoi de mail. En installant ssmtp avec la ligne de commande suivante, l'utilitaire mail est reconfiguré pour utiliser ssmtp

   sudo apt-get install ssmtp

 Suite à l'installation sendmail sera un raccourci pointant sur ssmtp

====E2. Configuration de ssmtp ====
 Il faut éditer 2 fichiers : /etc/ssmtp/ssmtp.conf et /etc/ssmtp/revaliases
 ssmtp.conf contient les paramètres d'authentifcation  
 revaliases permet de définir des handlers "compte unix appelant mail" --> service du client ssmtp à utiliser


Exemple : 
   # *************** Config file for sSMTP sendmail *************
   # The person who gets all mail for userids < 1000
   # Make this empty to disable rewriting.
   root=xavier.marquis@gmail.com
   
   # The place where the mail goes. The actual machine name is required no MX records are consulted. 
   # Commonly mailhosts are named mail.domain.com
   mailhub=smtp.gmail.com:587
   
   # Login/Passwd
   AuthUser=xavier.marquis@gmail.com
   AuthPass=freeman1979
   
   # Where will the mail seem to come from?
   rewriteDomain=gmail.com
   
   # The full hostname
   # hostname=localhost
   hostname=xms_rbpi2
   
   # Are users allowed to set their own From: address?
   # YES - Allow the user to specify their own From: address
   # NO - Use the system generated From: address
   FromLineOverride=YES
   
   UseTTLS=YES
   UseSTARTTLS=YES


====E3. Resolution des problemes gmail ====


It may take more than one step to fix this issue

1. Take the step mentioned earlier. Log into your google email account and then go to this link: https://www.google.com/settings/security/lesssecureapps and set "Access for less secure apps" to ON. Test to see if your issue is resolved. If it isn't resolved, as it wasn't for me, continue to Step #2.

2.Go to https://support.google.com/accounts/answer/6009563 (Titled: "Password incorrect error"). This page says "There are several reasons why you might see a “Password incorrect” error (aka 534-5.7.14) when signing in to Google using third-party apps. In some cases even if you type your password correctly." This page gives 4 suggestions of things to try.

For me, the first suggestion worked:

Go to https://g.co/allowaccess from a different device you have previously used to access your Google account and follow the instructions.
Try signing in again from the blocked app.