Resolved Problems with sending emails.

[DubDesigns]

Hello. I recently have installed Plesk on my dedicated home machine. Setting up the server and domains with no issues. But I've noticed that the emails are not working properly.

Error message from Plesk panel:

Screenshot

Captured with Lightshot

prnt.sc

I've done some research on Google and make sure port 25 is open. However, port 25 is definitely open and I have also tried temporarily disable the firewall.

Screenshot

Captured with Lightshot

prnt.sc

The machine is using Ubuntu 20.041 LTS.
Plesk Obsidian Web Admin Edition
Version 18.0.32 Update #2

 

[DubDesigns]

/var/log/maillog

Expand/Collapse Block: maillog

Jan 8 20:48:24 relaxed-kilby postfix/smtp[286607]: connect to gmail-smtp-in.l.google.com[173.194.220.26]:25: Connection timed out
Jan 8 20:48:24 relaxed-kilby postfix/smtp[286607]: connect to gmail-smtp-in.l.google.com[2a00:1450:4010:c05::1b]:25: Network is unreachable
Jan 8 20:48:42 relaxed-kilby dovecot: imap-login: Disconnected (auth failed, 2 attempts in 34 secs): user=<support@dubdesigns.org>, method=PLAIN, rip=62.248.234.173, lip=62.248.234.63, TLS: Connection closed, session=<6M93rGm4m+g++Oqt>
Jan 8 20:48:42 relaxed-kilby dovecot: imap-login: Disconnected (auth failed, 2 attempts in 34 secs): user=<lasku@verkkosuunnittelija.fi>, method=PLAIN, rip=62.248.234.173, lip=62.248.234.63, TLS: Connection closed, session=<vMR3rGm4mug++Oqt>
Jan 8 20:48:42 relaxed-kilby dovecot: imap-login: Disconnected (auth failed, 2 attempts in 34 secs): user=<trash@dubdesigns.org>, method=PLAIN, rip=62.248.234.173, lip=62.248.234.63, TLS: Connection closed, session=<QKp3rGm4meg++Oqt>
Jan 8 20:48:50 relaxed-kilby dovecot: imap-login: Disconnected (auth failed, 2 attempts in 8 secs): user=<lasku@verkkosuunnittelija.fi>, method=PLAIN, rip=62.248.234.173, lip=62.248.234.63, TLS: Connection closed, session=<6dZ+rmm4p+g++Oqt>
Jan 8 20:48:54 relaxed-kilby dovecot: imap-login: Disconnected (auth failed, 2 attempts in 12 secs): user=<trash@dubdesigns.org>, method=PLAIN, rip=62.248.234.173, lip=62.248.234.63, TLS: Connection closed, session=<W+t+rmm4qOg++Oqt>
Jan 8 20:48:54 relaxed-kilby dovecot: imap-login: Disconnected (auth failed, 2 attempts in 12 secs): user=<support@dubdesigns.org>, method=PLAIN, rip=62.248.234.173, lip=62.248.234.63, TLS: Connection closed, session=<c+x+rmm4qeg++Oqt>
Jan 8 20:48:54 relaxed-kilby postfix/smtp[286607]: connect to alt1.gmail-smtp-in.l.google.com[108.177.97.26]:25: Connection timed out
Jan 8 20:48:54 relaxed-kilby postfix/smtp[286607]: connect to alt1.gmail-smtp-in.l.google.com[2404:6800:4008:c00::1b]:25: Network is unreachable
Jan 8 20:49:24 relaxed-kilby postfix/smtp[286607]: connect to alt2.gmail-smtp-in.l.google.com[74.125.28.26]:25: Connection timed out
Jan 8 20:49:24 relaxed-kilby postfix/smtp[286607]: EA5B58815E3: to=<wili.wn99@gmail.com>, relay=none, delay=21815, delays=21724/0.01/90/0, dsn=4.4.1, status=deferred (connect to alt2.gmail-smtp-in.l.google.com[74.125.28.26]:25: Connection timed out)

 

[Bitpalast]

... However, port 25 is definitely open and I have also tried temporarily disable the firewall.

Screenshot

Captured with Lightshot

prnt.sc

It may be open on the machine, but is it also open for bi-directional traffic in your router and in your antivirus software?

 

[DubDesigns]

It may be open on the machine, but is it also open for bi-directional traffic in your router and in your antivirus software?

Did some research from our internet provider and seems like they've blocked port 25 permanently. Is it possible to change the port to something else?

 

[Bitpalast]

It is possible, but it is not feasible, because then your server won't be able to communicate with other mail servers on the Internet.

 

[DubDesigns]

It is possible, but it is not feasible, because then your server won't be able to communicate with other mail servers on the Internet.

Okay, I see. So the only option is getting an external relay web service?

 

[Bitpalast]

I honestly don't know your options. There are telecom access providers that block port 25, yes, but most of them don't. If you cannot access that port it might not be the best choice to run your server at home. Instead you might want to consider running it in a data center where you have all options available.

 

[DubDesigns]

I honestly don't know your options. There are telecom access providers that block port 25, yes, but most of them don't. If you cannot access that port it might not be the best choice to run your server at home. Instead you might want to consider running it in a data center where you have all options available.

Actually found a STMP relay server from the internet provider and now everything works fine