ESXi 6.x - how to allow outgoing connections to an SMTP server ?

Hello,

I've several ESXi servers with LSI raid card. LSI is providing a tool (stocli) that can display the RAID status, so I want to run a script that will filter the output of storcli and send an alert by mail if the RAID is faulty.

Script's ok, I've prepared a netcat code to create and send the email, but the firewall prevents outbound connection to my dedicated SMTP server.

Google keep telling me that I need to create a service file in /etc/vmware/firewall, reload the firewall and activate the firewall for that specific service, but though the "firewall refresh" command seems happy (no error), the "ruleset list" is not mentionning my service.

the mail.xml service file I'm using contains:

<ConfigRoot>

  <service id='0200'>

    <id>wMail</id>

    <rule id='0000'>

      <direction>outbound</direction>

      <protocol>tcp/protocol>

      <port type='dst'>25</port>

    </rule>

    <rule id='0001'>

      <direction>outbound</direction>

      <protocol>tcp/protocol>

      <port type='dst'>587</port>

    </rule>

   <enabled>true</enabled>

   <required>false</required>

  </service>

</ConfigRoot>

What am I doing wrong ?

What would be the correct way to achieve the same result (a working one, of course, not the same non-working result I have had so far 

Regards,