Unable to send messages

[Sultan Ghaznawi]

Thanks Thomas, it makes sense!

Regards,

Sultan

-----Original Message-----
From: Nathanael D. Noblet [mailto:nathanael at gnat.ca] 
Sent: Monday, March 21, 2016 6:51 PM
To: Sultan Ghaznawi
Cc: 'users'
Subject: Re: Unable to send messages

Hello,

  That's correct.

On Mon, 2016-03-21 at 18:44 -0400, Sultan Ghaznawi wrote:
> Thanks, Nathanael. Yes, I am testing this at home to if I can make it 
> work. We have SMTP servers at work that listen to several ports 
> including 26. If I understand correctly, all outbound messages will be 
> relayed to such an SMTP server on the internet which will then perform 
> the actual email delivery. Right?
> 
> Thanks,
> 
> Sultan
> 
> -----Original Message-----
> From: Nathanael D. Noblet [mailto:nathanael at gnat.ca]
> Sent: Monday, March 21, 2016 6:35 PM
> To: Sultan Ghaznawi
> Cc: 'users'
> Subject: Re: Unable to send messages
> 
> Ah yeah, I didn't know this wasn't a 'proper' server. Outgoing port
> 25 is often blocked by residential ISP providers / plans.
> 
> So your only solution is to have a relay host somewhere publicly 
> accessible and not listening on port 25 for example. You would then 
> configure your internal postfix system to use it as a relay. Which is 
> as simple as editing main.cf and setting
> 
> relayhost = [external.host.com:1025]
> 
> for example.
> 
> --
> Nathanael
> 
> On Mon, 2016-03-21 at 18:25 -0400, Sultan Ghaznawi wrote:
> > 
> > Hi Nathanael,
> >  
> > Thanks for the pointer, I checked my firewall and I have port 25 
> > opened for bi-directional traffic. I am not sure about postfix 
> > configuration as I kept everything as default during the Kolab 
> > installation process. However, I believe Rogers (my ISP in Canada) 
> > blocks port 25. I am not sure how that works since I am able receive 
> > mail (delivered to Kolab box on port 25?).
> >  
> > Is there a way to use another port or a different protocol (e.g.
> > secure)?
> >  
> > Thanks,
> >  
> > Sultan
> >  
> > From: Nathanael Noblet [mailto:nathanael at gnat.ca]
> > Sent: Sunday, March 20, 2016 10:58 PM
> > To: Sultan Ghaznawi
> > Cc: users
> > Subject: RE: Unable to send messages
> >  
> > Hello,
> >   So the only thing I can think is that somehow your firewall is 
> > blocking outbound port 25 OR you've configured postfix to use a 
> > relay host it can't reach. Try telneting to the MX server of the 
> > outbound server you were testing to narrow it further?
> > Nathanael
> > On Mar 20, 2016 3:08 PM, Sultan Ghaznawi <shghaznawi at telusmail.net>
> > wrote:
> > Hi Nathanael,
> >  
> > Many thanks for your response. What you are suggesting is what I 
> > thought of at the first place, however, I can ping any IP address 
> > from that box without a problem and all other tools, such as yum, 
> > curl, wget and everything else works. It seems the DNS is also set 
> > up properly, the only thing that might be an issue is if for some 
> > reason the firewall within the box is rejecting outbound requests 
> > from this application on a specific port. I did run the port 
> > white-listing command before installing Kolab.
> >  
> > Any other suggestions?
> >  
> > Sultan
> >  
> > From: Nathanael Noblet [mailto:nathanael at gnat.ca]
> > Sent: Saturday, March 19, 2016 12:16 AM
> > To: Sultan Ghaznawi
> > Cc: users
> > Subject: Re: Unable to send messages
> >  
> >  
> > On Mar 18, 2016, at 9:20 PM, Sultan Ghaznawi <shghaznawi at telusmail.
> > ne
> > t> wrote:
> >  
> > Hi Everyone,
> >  
> > I set up the Kolab 16 on CentOS 7 and everything went well. Here is 
> > what is happening:
> >  
> > 1.       I can send/receive emails between internal users (my domain 
> > within the box).
> > 2.       I can receive emails sent from outside my domain over the 
> > internet 3.       I am unable to send out messages. I send a 
> > message, I do not get an error in the UI, the /var/log/maillog shows 
> > “network is unreachable” and “timed out” messages. I ran the 
> > “lmtptest google.com” command and it shows network unreachable 
> > error.
> >  
> > It sounds like the error is completely unrelated to kolab. Can the 
> > server successfully resolve names? Does its default route work 
> > outbound? Can you grab websites using curl or wget on that server?
> > A
> > network unreachable error really seems unrelated to kolab or any 
> > server system at all. Try narrowing down the issue. Perhaps dig 
> > apple.com to see if you get an IP etc..
> >  
> > —
> > Nathanael
>