fix(notifier): force use of sender email in smtp from cmd (#2616)

This change addresses an issue with the usage of the full sender configuration option in the MAIL FROM SMTP command. If a user includes a name in the sender this shouldn't be sent in the MAIL FROM command, instead we should extract it and use just the email portion.

Fixes #2571

1 files changed, 35 insertions, 0 deletions

diff --git a/internal/configuration/decode_hooks.go b/internal/configuration/decode_hooks.go
new file mode 100644
index 000000000..b2012d9ff
--- /dev/null
+++ b/internal/configuration/decode_hooks.go
@@ -0,0 +1,35 @@
+package configuration
+
+import (
+	"fmt"
+	"net/mail"
+	"reflect"
+
+	"github.com/mitchellh/mapstructure"
+)
+
+// StringToMailAddressFunc decodes a string into a mail.Address.
+func StringToMailAddressFunc() mapstructure.DecodeHookFunc {
+	return func(f reflect.Kind, t reflect.Kind, data interface{}) (value interface{}, err error) {
+		if f != reflect.String || t != reflect.TypeOf(mail.Address{}).Kind() {
+			return data, nil
+		}
+
+		dataStr := data.(string)
+
+		if dataStr == "" {
+			return mail.Address{}, nil
+		}
+
+		var (
+			mailAddress *mail.Address
+		)
+
+		mailAddress, err = mail.ParseAddress(dataStr)
+		if err != nil {
+			return nil, fmt.Errorf("could not parse '%s' as a RFC5322 address: %w", dataStr, err)
+		}
+
+		return *mailAddress, nil
+	}
+}