[BlueOnyx:17441] Re: Relay email problem

[Michael Stauber]

Hi Tobias,

> So this means just the description in the GUI is wrong? This is a pity because then I am at my primary problem again.
> 
> But Michael: please clarify the description that it is clear that a hostname is only allowed if it is a static one.

Well, the thing here is that Sendmail doesn't really take the "static
DNS with dynamic IP" into account.

Usually when you enter a hostname there it is assumed that this hostname
doesn't show up with an ever changing IP address. Sendmail may do a
lookup once on that hostname and then uses the cached IP for a while. If
the IP changes while Sendmail is still using the cached result from last
time around, then you have a problem.

Which I think is exactly the problem you have.

It's neither Sendmails fault nor that of the GUI. Because I can almost
guarantee that Sendmail is not caching the result longer than the TTL of
the DNS record. So that part should work exactly as intended.

What TTL does DynDNS assign to their records?

Is your BlueOnyx using it's own DNS server to resolve records? Or is it
using any other DNS server to do that? If it is using another one, then
maybe that one caches records longer than the TTL of the records
actually say it should cache things?

As you can see, we quickly get to a point where we have many potential
spots which could cause or contribute to the problem.

-- 
With best regards

Michael Stauber