Question Port 25 is blocked despite an explicit firewall rule

[msinne]

Hello,

I'm using the msmtp relay addon/plugin for my php scripts to send mails (eg contact forms etc.)
Postfix and sendmail are deactivated.
I set up the external relay gateway correctly. The relay gateway sends through port 25.
I tried my scripts - no mail is going out.
I checked the ports with nmap. Port 25 is blocked.
I then put a firewall (the default plesk firewall) rule that opens tcp port 25, then
checked again with nmap, but port 25 is still blocked locally.
Where's the trick? Am I missing something or getting something wrong?

Best regards
Michael

 

[mow]

Ask your provider to open that port.

 

[msinne]

no I checked the port locally on the machine with nmap and it's closed.
I asked my ISP already and he said port 25 is not blocked.

 

[Kaspar]

I asked my ISP already and he said port 25 is not blocked.

By ISP (internet service provider) you mean the company providing you with an internet connection at the place you reside/work? Because you ought to ask your hosting/cloud provider if port 25 is open.

 

[msinne]

I meant my Hosting-provider

 

[Bitpalast]

If port 25 is blocked, you cannot mail anything through the server. Is that the case?

 

[msinne]

that's the case

 

[Bitpalast]

What's the output of
# sudo lsof -i -P -n | grep LISTEN | grep :25

 

[msinne]

no result

 

[Bitpalast]

O.k., I think what you are seeing is kind of an illusion. I think that everything is actually correctly set-up, but you are trying to connect to port 25 on your local system. However, there is no mail server on port 25 (or other ports) on your local server. When you use the MSMTP option, you do not have any local mail server or mail functions, so you have to make sure that any script where you send mails from is directly connecting to your external mail server. From what I understand you cannot combine the MSMTP option with a local mail functionality to submit mails on your server.

 

[msinne]

I'll have a try