Ubuntu
sendmail package

  1. Bug #1894379
  2. Comment #5

Comment 5 for bug 1894379

Revision history for this message
Brian Smith (avalon73) wrote :

Unfortunately I don't have any machines running Focal anymore to test with, and I didn't think to check if a AAAA DNS request was actually going over the wire when I had one.

It's easy enough to replicate, though, by using the smart host feature. On the machine running Focal:

- IPv6 address literal as a smart host works
- Named smart host with A and AAAA records uses the IPv4 address
- Named smart host with only a AAAA record results in a "host not found" bounce

There is no IPv4 fallback when no IPv4 addresses are in the DNS results.