There is a bug in VMS MAIL which is manifested when a foreign protocol address is entered at the To: or CC: prompts and the trailing double quote character, ", is omitted. For example
MAIL> send To: in%"user@domain %LIB-F-SYNTAXERR, string syntax error detected by LIB$TPARSE $Under older versions of OpenVMS, MAIL will go into an infinite loop rather than exit with the fatal error. This problem has nothing to do with PMDF and cannot be avoided; indeed, it occurs before PMDF is ever invoked by VMS MAIL.