The sendmail-doc package doesn't include the README
found in sendmail-8.11.6/sendmail/README which is different from the
After upgrading to redhat 7.1 or 7.2 sometimes maildelivery
The explanation is found in sendmail/README:
`When attempting to canonify a hostname, some broken name servers will
return SERVFAIL (a temporary failure) on T_AAAA (IPv6) lookups. If you
want to excuse this behavior, compile sendmail with
-D_FFR_WORKAROUND_BROKEN_NAMESERVERS and add WorkAroundBrokenAAAA to your
ResolverOptions setting. However, instead, we recommend catching the
problem and reporting it to the name server administrator so we can rid the
world of broken name servers.
I have added the docu and this compiletime flag, but don't change the
configuration to enable the workaround by default.
Florian La Roche