Even when running with Netdata support, LISTSERV tries to fold long lines both so that they look better in the archives and to avoid ending up with outrageously long lines that SMTP will not be able to process, if there were many "To:" recipients for instance (the only thing worse than a massive spam is a massive spam that brings some mail systems down). But in this case LISTSERV incorrectly used the folding algorithm for address lines, where it is indeed ok to split around a period. A fix is available from [log in to unmask] for customers with a service contract. Eric