diff --git a/utils/mail.go b/utils/mail.go
index 0d4645c..371c294 100644
--- a/utils/mail.go
+++ b/utils/mail.go
@@ -35,8 +35,6 @@ import (
 	"bytes"
 	"io"
 	"net/mail"
-	"os"
-	"os/exec"
 	"text/template"
 
 	gomail "github.com/go-mail/mail"
@@ -46,13 +44,20 @@ import (
 	"github.com/yuin/goldmark/renderer/html"
 )
 
-const sendmail = "/usr/sbin/sendmail"
-
 var (
-	MailFrom                 = mail.Address{Name: "Fred From happyDNS", Address: "contact@happyDNS.org"}
+	// MailFrom holds the content of the From field for all e-mails that
+	// will be send.
+	MailFrom = mail.Address{Name: "Fred From happyDNS", Address: "contact@happyDNS.org"}
+
+	// SendMethod is a pointer to the current global method used to send
+	// e-mails.
 	SendMethod gomail.Sender = &SystemSendmail{}
 )
 
+// SendMail takes a content writen in Markdown to send it to the given user. It
+// uses Markdown to create a HTML version of the message and leave the Markdown
+// format in the text version. To perform sending, it relies on the SendMethod
+// global variable.
 func SendMail(to *mail.Address, subject, content string) (err error) {
 	m := gomail.NewMessage()
 	m.SetHeader("From", MailFrom.String())
@@ -118,36 +123,3 @@ func SendMail(to *mail.Address, subject, content string) (err error) {
 
 	return
 }
-
-type SystemSendmail struct{}
-
-// system_sendmail uses the sendmail command to submit the given message
-func (t *SystemSendmail) Send(from string, to []string, msg io.WriterTo) error {
-	cmd := exec.Command(sendmail, "-t")
-	cmd.Stdout = os.Stdout
-	cmd.Stderr = os.Stderr
-
-	pw, err := cmd.StdinPipe()
-	if err != nil {
-		return err
-	}
-
-	err = cmd.Start()
-	if err != nil {
-		return err
-	}
-
-	if _, err = msg.WriteTo(pw); err != nil {
-		return err
-	}
-
-	if err = pw.Close(); err != nil {
-		return err
-	}
-
-	if err = cmd.Wait(); err != nil {
-		return err
-	}
-
-	return nil
-}
diff --git a/utils/mail_systemsendmail.go b/utils/mail_systemsendmail.go
new file mode 100644
index 0000000..3aced8b
--- /dev/null
+++ b/utils/mail_systemsendmail.go
@@ -0,0 +1,75 @@
+// Copyright or © or Copr. happyDNS (2020)
+//
+// contact@happydns.org
+//
+// This software is a computer program whose purpose is to provide a modern
+// interface to interact with DNS systems.
+//
+// This software is governed by the CeCILL license under French law and abiding
+// by the rules of distribution of free software.  You can use, modify and/or
+// redistribute the software under the terms of the CeCILL license as
+// circulated by CEA, CNRS and INRIA at the following URL
+// "http://www.cecill.info".
+//
+// As a counterpart to the access to the source code and rights to copy, modify
+// and redistribute granted by the license, users are provided only with a
+// limited warranty and the software's author, the holder of the economic
+// rights, and the successive licensors have only limited liability.
+//
+// In this respect, the user's attention is drawn to the risks associated with
+// loading, using, modifying and/or developing or reproducing the software by
+// the user in light of its specific status of free software, that may mean
+// that it is complicated to manipulate, and that also therefore means that it
+// is reserved for developers and experienced professionals having in-depth
+// computer knowledge. Users are therefore encouraged to load and test the
+// software's suitability as regards their requirements in conditions enabling
+// the security of their systems and/or data to be ensured and, more generally,
+// to use and operate it in the same conditions as regards security.
+//
+// The fact that you are presently reading this means that you have had
+// knowledge of the CeCILL license and that you accept its terms.
+
+package utils
+
+import (
+	"io"
+	"os"
+	"os/exec"
+)
+
+// sendmail contains the path to the sendmail command
+const sendmail = "/usr/sbin/sendmail"
+
+// SystemSendmail uses the sendmail command to send message
+type SystemSendmail struct{}
+
+// Send sends an e-mail to the given recipients using the sendmail command.
+func (t *SystemSendmail) Send(from string, to []string, msg io.WriterTo) error {
+	cmd := exec.Command(sendmail, "-t")
+	cmd.Stdout = os.Stdout
+	cmd.Stderr = os.Stderr
+
+	pw, err := cmd.StdinPipe()
+	if err != nil {
+		return err
+	}
+
+	err = cmd.Start()
+	if err != nil {
+		return err
+	}
+
+	if _, err = msg.WriteTo(pw); err != nil {
+		return err
+	}
+
+	if err = pw.Close(); err != nil {
+		return err
+	}
+
+	if err = cmd.Wait(); err != nil {
+		return err
+	}
+
+	return nil
+}
diff --git a/utils/mail_templates.go b/utils/mail_templates.go
index 568a1d5..8122997 100644
--- a/utils/mail_templates.go
+++ b/utils/mail_templates.go
@@ -31,6 +31,7 @@
 
 package utils
 
+// mailHTMLTpl is the HTML template used for email.
 const mailHTMLTpl = `
 <!DOCTYPE html>
 <html lang="{{ .Lang }}">
@@ -163,8 +164,9 @@ const mailHTMLTpl = `
   </body>
 </html>`
 
+// mailHTMLTpl is the template used for text emails.
 const mailTXTTpl = `{{ .Content }}
 
--- 
+--
 Fred - customer support @ happyDNS
 Legal notice: https://www.happydns.org/en/legal-notice/`
diff --git a/utils/password.go b/utils/password.go
index f11e473..8ed4852 100644
--- a/utils/password.go
+++ b/utils/password.go
@@ -37,6 +37,7 @@ import (
 	"strings"
 )
 
+// GeneratePassword randomly generates a secure 12 chars long password.
 func GeneratePassword() (password string, err error) {
 	// This will make a 12 chars long password
 	b := make([]byte, 9)