MF-1521 - Fix email headers (#1522)

Signed-off-by: Ivan Milosevic <iva@blokovi.com>

docker/.env

@@ -309,6 +309,7 @@ MF_SMTP_NOTIFIER_DB_USER=mainflux
 MF_SMTP_NOTIFIER_DB_PASS=mainflux
 MF_SMTP_NOTIFIER_DB=subscriptions
 MF_SMTP_NOTIFIER_TEMPLATE=smtp-notifier.tmpl
+MF_SMTP_NOTIFIER_FROM_ADDR=from@example.com
 
 
 ### SMPP Notifier

docker/addons/smtp-notifier/docker-compose.yml

@@ -55,6 +55,7 @@ services:
       MF_EMAIL_FROM_NAME: ${MF_EMAIL_FROM_NAME}
       MF_EMAIL_TEMPLATE: ${MF_EMAIL_TEMPLATE}
       MF_SMTP_NOTIFIER_TEMPLATE: ${MF_SMTP_NOTIFIER_TEMPLATE}
+      MF_SMTP_NOTIFIER_FROM_ADDR: ${MF_SMTP_NOTIFIER_FROM_ADDR}
     ports:
       - ${MF_SMTP_NOTIFIER_PORT}:${MF_SMTP_NOTIFIER_PORT}
     networks:

docker/templates/smtp-notifier.tmpl

@@ -1,4 +1,4 @@
-To: {{.To}}
+To: {{range $index, $v := .To}}{{if $index}},{{end}}{{$v}}{{end}}
 From: {{.From}}
 Subject: {{.Subject}}
 {{.Header}}

docker/templates/users.tmpl

@@ -1,4 +1,4 @@
-To: {{.To}}
+To: {{range $index, $v := .To}}{{if $index}},{{end}}{{$v}}{{end}}
 From: {{.From}}
 Subject: {{.Subject}}
 {{.Header}}

internal/email/email.go

@@ -6,8 +6,9 @@ package email
 import (
 	"bytes"
 	"fmt"
-	"html/template"
+	"net/mail"
 	"net/smtp"
+	"text/template"
 
 	"github.com/mainflux/mainflux/logger"
 	"github.com/mainflux/mainflux/pkg/errors"
@@ -89,7 +90,8 @@ func (a *Agent) Send(To []string, From, Subject, Header, Content, Footer string)
 		Footer:  Footer,
 	}
 	if From == "" {
-		tmpl.From = a.conf.FromName
+		from := mail.Address{Name: a.conf.FromName, Address: a.conf.FromAddress}
+		tmpl.From = from.String()
 	}
 
 	if err := a.tmpl.Execute(email, tmpl); err != nil {