Noel Jones a écrit :
> Thomas wrote:
>> Thomas Ackermann wrote:
>>> So, does anybody know what technically is the difference between the
>>> use with and without the signs?
>>> I mean, what network things may happen or not happen?
>>
>> Nobody knows the technical differences?
>>
>> :-(
>
> ... more likely nobody cares, because postfix behavior is documented.
>
> When the relayhost is a hostname enclosed by "[ ]" brackets, postfix
> asks for an A record and does not ask for an MX record.
>
> If relayhost is an IP address enclosed by brackets, postfix uses that IP
> with no additional lookups.
>
> If realyhost is a hostname with no brackets, postfix will request an MX
> record, if no MX exists, postfix will then request an A record.
>
> If relayhost is an IP address with no brackets, postfix will request a
> PTR lookup to find the hostname, then request an MX lookup on that
> hostname. If no MX record exists, then an A record is requested for the
> hostname. Either the MX lookup or the A lookup may return a result
> different from the original bare IP; this is why you should always
> enclose a literal IP address relayhost in brackets.
>
hmmm. smtp(8) doesn't list "naked IP" as a valid destination format. only
domainname
domainname:port
[domainname]
[domainname]:port
[address]
[address]:port
(nor does http://www.postfix.org/postconf.5.html#relayhost).
> Actual lookups are performed by system libraries, not by postfix.
>
>
