> You have records which absolutely > need to be public: SPF, MXs--mail won't work otherwise.
I hope I misunderstood the intended meaning or context of those words, because their literal, context free meaning that SPF and MX records are required by SMTP is wrong. SPF might be considered required by unsolicited or semi-solicited bulk mail senders to help large scale "free" mailbox providers gauge the legitimacy of mail advertisements. Otherwise SPF is *not* required. As proof consider both this message and the DCC mailing lists (i.e. old school solicited bulk mail.) In some cases SPF harms SMTP delivery, especially when combined with DMARC. Because I'm in neither the email advertising business nor the large scale "free" mailbox businesses, the only unambiguous use I've found for SPF records is to try to prevent mail. I publish SPF RRs for some domains that send no mail in order to reduce NDRs or "bounces" of forged mail from bad SMTP servers (mail receivers) that fail to validate SMTP Rcpt_To values during the SMTP transaction. The case for MX records being required for SMTP is clear. In the absense of an explicit MX record, the standards require SMTP clients (mail senders) to infer an implicit MX from derived A or AAAA records. Vernon Schryver v...@rhyolite.com _______________________________________________ Please visit https://lists.isc.org/mailman/listinfo/bind-users to unsubscribe from this list bind-users mailing list bind-users@lists.isc.org https://lists.isc.org/mailman/listinfo/bind-users
