Resolved Block port 25 outbound only

[Cordal]

Server operating system version

Debian 11

Plesk version and microupdate number

18.0.52 Actualización 2

Estoy creando una regla en el firewall de plesk que bloquea el puerto 25 solo para salida, pero falta algo ya que puedo continuar enviando correo usando ese puerto, adjunto una captura de pantalla.

 

[Maarten.]

We use the English language on this forum. Please translate your question using deepl.com before posting.

 

[Cordal]

We use the English language on this forum. Please translate your question using deepl.com before posting.

We use the English language on this forum. Please translate your question using deepl.com before posting.

Sorry I forgot to put the translation:

I am creating a rule in plesk firewall that blocks port 25 for outbound only, but something is missing since I can continue to send mail using that port, I am attaching a screenshot.

 

[Kaspar]

The rule shown in the screenshot only block outbound traffic on port 25 for the 192.168 range. Which is an private IP address range. There usually isn't a whole lot of activity on that IP range unless you have a local network running. Which makes me wonder why you want to block this IP range specifically?

 

[Cordal]

I have put that range because it is the one that came in the example, what I want to block is all the outgoing traffic through port 25, what should I put in that case?

 

[Cordal]

I understand that if I leave that field blank, it will block the output to any IP?

 

[Kaspar]

I understand that if I leave that field blank, it will block the output to any IP?

Yes

 

[Cordal]

Thank you very much, that was it

 

[Cordal]

The problem now comes to me because when closing the output port 25, it does not send through 587 or 465 either

 

[Kaspar]

I assume you want to block port 25 so email apps (Thunderbird, Outlook, Apple mail, ect) cannot use it to send e-mail because it's an insecure connection?

However port 25 is also used by a sever for talking to other (mail) servers. So if you want send email to an Gmail email address (for example) your server cant connect to to the Gmail servers to send the email. So if you block 25 no email can be send at all.

 

[Cordal]

Thanks