Forwarding port 25 on Connect Box 3

gevreyc · 2023-07-06T11:59:33+00:00

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gevreyc

I am running my own SMTP server on my network.

Why does the Conect Box 3 port forwarding page denies me to add this rule?

Is there a workaround?

@Daniele_Sunrise, you may know?

Thanks for any help.

Daniele_Sunrise

gevreyc This port is blocked by us for security reasons. Please use the ports for an authenticated SMTP (port 587).

Greetings
Daniele

gevreyc

Daniele_Sunrise I will try that. Thanks

gevreyc

Daniele_Sunrise Apologies if I have been unclear: the port 587 is typically used for client-to-server communication for sending email, not server-to-server communication for receiving it, which is what I need. The port 25 is required in my case, otherwise I cannot RECEIVE emails on my server.

Can you please help?

Christophe

Daniele_Sunrise

gevreyc We have no way to bypass the lock. You need a business product in this case and we ask you to search for a solution via business.

Greetings
Daniele

gevreyc

Daniele_Sunrise

Thank you, Daniele. However, I must express my disappointment due to control issues with my box since transitioning to Sunrise from the traditional operator. This has been the key concern in my experience. Sunrise’s attention to this matter would be greatly appreciated.

Daniele_Sunrise

gevreyc Desperately we have no chance to do something here. Can I ask you, for what you need Port 25, as newly Mails are sent secured via Port 587/465. We do not allow unsecured sending of Mails anymore. my Hosting Provider offers on my Mailserver this ports and 25 is closed too.

For POP3 Port 110 is needed
For IMAP Ports 143/993 are needed
For SMTPS Ports 465, new 587 are needed

Greetings
Daniele

gevreyc

For SMTPS you need proper certificates, I have only the Lets Encrypt ones.

Even though I have configured Postfix and Dovecot for secure SMTP, somehow, I don’t get any incoming emails. I did check my configuration and certifificates. So I presumed, some mail servers only use port 25 to deliver emails to me.

openssl s_client -starttls smtp -connect mybox.org:587 -crlf

All this works well, helo test too.

I may be wrong.

Daniele_Sunrise

gevreyc I am not a mail pro, maybe other users have more tips how you can configure the mailserver without port 25.

Port 587 is definitely open for you, all other mentioned ports are closed, I just checked it via https://www.yougetsignal.com/tools/open-ports/.

Greetings
Daniele

haeusebio

Hello,

I have an similar Issue, since I got my new Internet Router, I’m not able to open Port 25 for INCOMING mails, since it has been blocked. With the old router everything worked fine, since it’s possible to receive incoming mails.
I also checked the vendor’s guide:

Check if your ISP blocks port 25. Some ISPs do so to prevent spamming by their customers. If port 25 is blocked, you won’t be able to host a mail server under this IP address. Please contact your ISP to unblock port 25.

BTW: Would a bridge i.e to a Fritzbox Router fix this issue?

Thanks

gevreyc

haeusebio this is what I did. I bought an Asus router and only use the ConnectBox in bridge mode. Problem solved.

haeusebio

gevreyc Hi, thank you very much for your response. Great, can you please tell me which model you bought? Not that I’ll buy the wrong one. Many thanks!