Wietse Venema via Postfix-users: > Wietse Venema via Postfix-users: > > It's a rather long explanation for "why not do X". like several > > times longer than the text that explains what protocol preferences > > do. And this is the only place where adding that text would help. > > I updated the text a little:
I'm adding a section to smtp_address_preferences, about when not to use this setting. Wietse Notes for mail delivery between sites that have both IPv4 and IPv6 connectivity: * Some remote SMTP servers will flag messages received over IPv6 as more 'spammy' than messages received over IPv4. This may be because the Postfix SMTP client's IPv6 address lacks a proper PTR record, or because the client shares an IPv6 address block with bad users. To achieve consistent delivery performance, don't tweak the smtp_address_preference setting; instead, receive mail over both IPv4 and IPv6, and deliver mail only over IPv4. /etc/postfix/main.cf: inet_protocols = all /etc/postfix/master.cf smtp ...other fields... smtp -o inet_protocols=ipv4 * The setting "smtp_address_preference = ipv6" is unsafe. [Existing text omitted for brevity] _______________________________________________ Postfix-users mailing list -- postfix-users@postfix.org To unsubscribe send an email to postfix-users-le...@postfix.org