Task mentions (#926)

Co-authored-by: kolaente <k@knt.li>
Reviewed-on: https://kolaente.dev/vikunja/api/pulls/926
Co-authored-by: konrad <konrad@kola-entertainments.de>
Co-committed-by: konrad <konrad@kola-entertainments.de>

pkg/cmd/testmail.go

@@ -42,7 +42,7 @@ var testmailCmd = &cobra.Command{
 	Run: func(cmd *cobra.Command, args []string) {
 		log.Info("Sending testmail...")
 		message := notifications.NewMail().
-			From(config.MailerFromEmail.GetString()).
+			From("Vikunja <"+config.MailerFromEmail.GetString()+">").
 			To(args[0]).
 			Subject("Test from Vikunja").
 			Line("This is a test mail!").