The attached ebuild adds IPv6 support to sendmail if wanted per ipv6 USE flag. Reproducible: Always Steps to Reproduce:
Created attachment 18581 [details] sendmail ebuild with IPv6 support
Sorry, should probably have submitted a patch instead. The only changed line compared to 8.12.10.ebuild is the "use ipv6 && ..." one
*** Bug 30010 has been marked as a duplicate of this bug. ***
Latest sendmail ebuilds support ipv6 USE flag.