On 2016-12-13, Mik J <mikyde...@yahoo.fr> wrote: > Peter, you use greylists but I read somewhere that gmail servers change their > IPs when they retry to send the mails.
It used to be common to attempt a few deliveries from a "main" smarthost and then push to a "slow retry" host, it seemed that this was particularly popular with some larger Exim users. Nowadays it's more likely that the sending servers at large mail providers are just behind NAT pools (and in some cases, also multiple SMTP senders running from a common queue). No point wasting precious v4's when the bottleneck is storage i/o.
