> ?example.com????? smtp:[gateway.example.com]
>
> gateway.example.com? resolves to 3 IP addresses...
>
> - Will Postfix try to resolve gateway.example.com for each and every email?
Email message?
> - What happens if one of the IPs are not responding?
That is handled as required by the SMTP standard.
> - If an email goes to the Deferred queue, when later on Postfix
> tries to send it again, does it try with the same IP of the previous
> try?
The Postfix SMTP client does not remember IP addresses that were
tried during previous deliveries.
Wietse
