CentOS - Jan 2020 - can't send email from my new centos 8

Hello to all!
I apologize in advance, for the following could be too simple, but I can't
figure it out.
I configured a vps using centos 8, all is working fine but I'm not able to
send email from this server.
I tried
$ telnet smtp.mailtrap.io 25 but it doesn't work
yet
$ telnet www.google.ca 80 does work
and particularly
$ telnet smtp.mailtrap.io 2525 does work too.
I temporarily disabled the firewall, and selinux, but no luck.
Can anyone provide any pointers?

Thanks in advance,
--
Victor
PS: I'm sorry if there were English spelling errors.

On Mon, Jan 20, 2020 at 06:04:47PM -0300, V. M. Tame-Reyes
wrote:
> I apologize in advance, for the following could be too simple, but I
can't
> figure it out.
> I configured a vps using centos 8, all is working fine but I'm not able
to
> send email from this server.
> I tried
> $ telnet smtp.mailtrap.io 25 but it doesn't work
> yet
> $ telnet www.google.ca 80 does work
> and particularly
> $ telnet smtp.mailtrap.io 2525 does work too.
> I temporarily disabled the firewall, and selinux, but no luck.
> Can anyone provide any pointers?
Are you configuring your VPS running CentOS 8 to run an SMTP server on
port 25, or are you trying to make your VPS running CentOS 8 talk to
an external SMTP server?

It sounds like you are trying to make your VPS talk to an external
SMTP server.  By default, the firewall shouldn't prevent outbound
connections.  However, some VPS providers, as well as residential
ISPs, do block outbound traffic to port 25, in an attempt to prevent
compromised systems from sending spam.  I suggest you look at the
documentation for your VPS provider and see if you are permitted to
send SMTP mail from the host.  You may need to relay mail through an
authenticated SMTP relay run by the VPS provider.

-- 
Jonathan Billings <billings at negate.org>

Thank you very much Jonathan!
As you mentioned, it's an issue with my provider, they are blocking the
ports by default.
Thanks again!
--
Victor

On Mon, Jan 20, 2020 at 6:24 PM Jonathan Billings <billings at negate.org>
wrote:
> On Mon, Jan 20, 2020 at 06:04:47PM -0300, V. M. Tame-Reyes wrote:
> > I apologize in advance, for the following could be too simple, but I
> can't
> > figure it out.
> > I configured a vps using centos 8, all is working fine but I'm not
able
> to
> > send email from this server.
> > I tried
> > $ telnet smtp.mailtrap.io 25 but it doesn't work
> > yet
> > $ telnet www.google.ca 80 does work
> > and particularly
> > $ telnet smtp.mailtrap.io 2525 does work too.
> > I temporarily disabled the firewall, and selinux, but no luck.
> > Can anyone provide any pointers?
>
> Are you configuring your VPS running CentOS 8 to run an SMTP server on
> port 25, or are you trying to make your VPS running CentOS 8 talk to
> an external SMTP server?
>
> It sounds like you are trying to make your VPS talk to an external
> SMTP server.  By default, the firewall shouldn't prevent outbound
> connections.  However, some VPS providers, as well as residential
> ISPs, do block outbound traffic to port 25, in an attempt to prevent
> compromised systems from sending spam.  I suggest you look at the
> documentation for your VPS provider and see if you are permitted to
> send SMTP mail from the host.  You may need to relay mail through an
> authenticated SMTP relay run by the VPS provider.
>
> --
> Jonathan Billings <billings at negate.org>
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>