On Wed, 11 May 2011 16:51:58 -0400 Michael Scheidell <michael.scheid...@secnap.com> wrote:
> ie: qmail, postfix, exchange, sendmail, all (can) send a 4xx after > rcpt to. Indeed. > because thats what the RFC's say. Note: I said "badly-written SMTP software", not "software that adheres to the RFCs". In the real world, 4xx after RCPT breaks a non-zero number of SMTP clients. Regards, David.
