[ SOLVED] new ISPconfig 3.3.1p1 installation does not deliver mails - even telnet :25 fails

I installed a complete new ISPconfig 3.3.1p1 over a Hetzner Debian 11 basic image, no specials, just standard.

Problem: My first an only email domain accepts mails to deliver, but outgoing mails to different recipient domains are blocked...

0687C420A2 2558 Sun Mar 29 15:50:02 [email protected]
(connect to mx01.emig.gmx.net[212.227.17.5]:25: Connection timed out)
[email protected]

I tried

telnet mx01.emig.gmx.net 25​

which works on other servers, but here: no contact.

ufw status is empty.

Any idea?

 

I install Debian myself, the images provided by hosters seem to be quite iffy always.
But current problem may be port 25 outgoing is blocked by your hoster. Unless you have asked for that port to be opened it probably is.
Check by logging in to that host and trying to connect somewhere else using port 25.

 

okay... sorry. NO ISPconfig related issue.

Hetzner issue...

Ports 25 and 465 are BLOCKED on their cloud servers, you can ASK them to unblock them, but MY server is to new....

Their "docs" say:
Warum kann ich keine Mails von meinem Server verschicken?
Leider ist der gezielte Versand von Spam-Mails ein großes Problem unter Cloud-Anbietern. Um dem bestmöglich entgegenzuwirken, blockieren wir bei Hetzner den ausgehenden Datenverkehr der Ports 25 und 465 standardmäßig auf allen Cloud Servern. Diese Vorsichtsmaßnahme ist unter Cloud-Anbietern weit verbreitet und hilft die missbräuchliche Nutzung der Ports zu verhindern. Bevor wir diese Ports für neue Kunden entsperren, möchten wir ein gewisses Vertrauen aufbauen. Sobald Sie seit mindestens einem Monat registriert sind und mindestens eine Rechnung bezahlt haben, können Sie aber bei einem konkreten Anwendungsfall mittels des Limit-Formulars eine Anfrage zur Entsperrung der Ports 25 und 465 stellen. In der Anfrage können Sie uns Ihren Fall schildern und weitere Details nennen. Jede Anfrage wird einzeln überprüft.

Alternativ kann auch Port 587 zum Versenden von E-Mails über externe Dienstleister/Mailservices genutzt werden. Port 587 ist nicht blockiert und es ist auch keine Limit-Anfrage erforderlich, um diesen zu nutzen.

 

Can I switch the delivering port of postfix from 25 to 587?

 

Exactly this is the problem. I never had that problem before, on NetCup I never had that.

My problem now is: everything else works perfect, and I moved a lot of services to this new host in the lasst days, NOW having this problem... I really cannot wait a MONTH until they open that port for me...

 

No. Mailsystem to Mailsystem communication will always be on port 25. What they describe in their docs is using a external SMTP Relay over port 587.

Try contacting them, describe your problem and see if they can make an exception for you. I think a customer that calls them and explains the situation is enough "proof" for them to allow your request even if the 4 week period is not over yet.

 

well... hetzner.com completely blocks this kind of "questions". They explicitely tell you "no telephone support for this", and trying to open a support ticket is blocked too....

So I moved the new mailboxes again to another server.

But the mails generated on this machine are still stuck in the queue.

Can I configure ISPconfig to send mails via a smart relay? Then I could use port 587!

I know I could try that in the postfix config directly, but I don't want to break the ISPconfig configuration by to many manual configured stuff

 

great - and very simple. I put in there the IP-address plus port 587, like 11.22.33.44:587, and now it works fine!

THANKS!