> On Mar 25, 2017, at 9:51 PM, Doug Barton <domain_name_t...@yahoo.com> wrote: > >> See >> >> http://www.postfix.org/postconf.5.html#inet_protocols >> http://www.postfix.org/postconf.5.html#smtp_address_preference >> >> If IPv6 is explicitly preferred, rather than randomly selected as with: >> >> smtp_address_preference = any >> >> then an MX host with sufficiently many IPv6 addresses will never be >> tried over IPv4 because the number of connection attempts and SMTP >> sessions are limited: >> >> http://www.postfix.org/postconf.5.html#smtp_mx_address_limit >> http://www.postfix.org/postconf.5.html#smtp_mx_session_limit >> >> One or the other might be exceeded before any IPv4 addresses are >> tried. > > That makes sense, thanks. It might be nice to have that information, or a > pointer to it, included in postconf(5).
Patches welcome, send to this list or via: https://github.com/vdukhovni/postfix/pulls -- Viktor.
