Re: [gentoo-server] Strange Mailserver Problem with dynamic DN [Solved]

[Rene Zbinden]

You were right. Problem solved. Thanks.

Florian Sesser wrote:

>Hi,
>
>My first guess would be that your ISP, solnet, is blocking your port 25.
>
>Their MX can connect to yours because it is in 'their' network, but their
>firewall rules prohibit anything coming from their upstream provider to
>connect to their clients (maybe to prevent spam or what ever, maybe just
>for lameness).
>
>You could ask your provider for being unblocked (dumb idea when using a
>large ISP?). I don't know about your DynDNS provider, but if you really
>need a local MX you could switch to no-ip.com: they offer some service to
>get exactly around the problem you have, pretty cheap IIRC. I don't know
>how they implement this, i guess they set the DNS MX records to one of
>their servers and then forward them to some other port on your machine.
>
>
>
>>I am using DNS Made Easy (like DynDNS) to point my Domain to my dynamic
>>IP address. Now almost everthing works. I can send mails outside my
>>domain but when I want to send an email to myself something strange
>>happens:
>>When I send an Email from my ADSL provider (solnet.ch) then I can
>>receive the email. Here the postfix log:
>>
>>
>>
>[... mucho log entrys only showing mail which is properly received ...]
>
>
>>But when I send a message from another account (bluewin.ch) then I NEVER
>>receive the mail and I get no error messages. It seems that those emails
>>go to nirvana without notification.
>>
>>
>
>i don't know about how mail servers react to ports being blocked. could be
>some/most/all really give up w/o notification. If Solnet *drops* packets
>to your port 25 this is probable. (someone correct me on this one if i'm
>wrong please?)
>
>HTH,
>
>Flo
>
>
>