On 13 Feb 99, at 0:23, Winship <[log in to unmask]> wrote: > I know that in some systems mail can be truncated because the system > interprets a period (.) in the fist column as an end of file flag. > Can the same thing happen with an underline (_) in the first col? > > Douglas It is singular to a single dot on a line of its own, and has to do with the fact that some of the mail servers are compatible with the Internet standards only partially. It is not a problem with LISTSERV, but rather with the mail transfer agents at the side of some subscribers, the problem does not exist with underscore. On SMTP each mail message is "enveloped" with the SMTP commands for posting it - this is called "the SMTP envelope". Acorrding to SMTP standards (RFC821) each BODY of a message is ended with the combination "<cr>.<cr>" (without the quotes) which means a dot on a line of its own, and this tells the SMTP server that now the transfer of the message body is finished. Now you may address a question: "So how a mailer should handle a <cr><dot><cr> if it appears in the body of the message?", and RFC821 also address this question, by instructing that the server of the sender to replace this combination with another one, and instructing the server of the recipient to replace it back (By truncating all text to the right of a period in column one). In some systems, this doesn't work correctly along the way of the message, and the trasform back to <cr><dot><cr> occurs to early. As a result the next server in the route understand the combination as if the message body has ended, and ignores the rest of the body as it can neither understand it as SMTP commands (security hole?) The problem is very clear in digested messages if one of the recipients uses this combination in his signature Uzi Paz