|reply to Steve |
Re: DNS - A, MX and PTR records - Silly quesiton
said by Steve:sorry, you lost me. said by tomdlgns: ETRN
The idea is that the servers listed as secondary MX servers have some out-of-band way of knowing when the primary servers are back online.
is an in-band
way of knowing this.
SteveI know your IP addressConsultant
Yorba Linda, CA
When the final mailserver is back up, it can phone home to the backup (via port 25/tcp) and use the ETRN command that essentially says "This would be a great time to scan your outgoing queue", at which time it presumably finds that it can consummate the final delivery.
No out-of-band mechanism required.
Stephen J. Friedl | Unix Wizard | Security Consultant | Orange County, California USA | my web site
ok, but were you correcting something i posted or adding more information?
i just copy/pasted from the website and included a link.