OK, before I make any comments let's list your other posts first.
Mail filter External
https://forums.koozali.org/index.php/topic,54977.msg289484.html#msg289484"how I can forward all outbound email traffic to a set of public IPs/subnets which is my email filter external"
mxbackup contrib on sme 10/Multiple domains in One sever
https://forums.koozali.org/index.php/topic,54979.msg289491.html#msg289491" found in contribs mxbackup is this being supported in the current version of koozali ?" (built but no real testing and probably not working correctly)
Outlook issue when receiving the email with picture attachements
https://forums.koozali.org/index.php/topic,54984.msg289527.html#msg289527" does anyone enconter issue when the client recieve the email from smtp server the image is not displayed correctly this includes excel files.."
windows 7 client not able to authenticate via pop3 and smtp
https://forums.koozali.org/index.php/topic,54985.msg289528.html#msg289528"do we have work around for windows 7 client not able to authenticate or pop3 and smtp"
(Do not ask for support with unsupported versions of software - which I think will almost certainly apply here)
You really are thrashing around trying to make your unsupported old software work rather than doing the right thing and upgrading properly.
You are running:
Win7 - unsupported
Outlook 2010 - unsupported as of Oct 2015 unless you have extended support to 2020
Outlook 2016 - unsupported as of Oct 2020 unless you have extended support to 2025
The system is set up on default with no spam filter nor RBL and SBL this is due to I have an external mail filter.
Default - I somehow doubt that bearing mind the above.
How is the mail passed to/retrieved from the external filter service?
What are your domains so we can check DNS?
Also users are retrieving email via IMAP/POP3 both are SSL with outgoing SSL 455 port.
Retrieving from your server, the filter server?
Why POP when you have IMAP? How is the POP set up?
Any other forwarding on the server? Forwarding to groups?
Users are using Outlook 2010 for most of it. I have no issue with regard to LAN connectivity. I am currently looking at the office version that could be the culprit for this duplicate email I am encountering.
Doing a test now with Outlook 2016 running parallel with the users using 2010 to see if the higher versions of office has no duplicate email
See above about unsupported systems
**just to add on this I tried to check webmail I see double email also. So I think its a bug in the system.
So I think it is highly likely it is a problem of your own making.
So stop guessing, start reading the wiki too understand how your server and its services work and how to debug things, and start providing us with some details on your server. You ought to take a look in your logs and see they are telling you.
You have to remember that we are not sitting in front of your server or clients so you need to describe accurately what you observe and furnish us with full details. Otherwise we are guessing as much as you are.
Either do:
/sbin/e-smith/audittools/newrpms
/sbin/e-smith/audittools/repositories
/sbin/e-smith/audittools/templates
Or go to server-manager, Miscellaneous, Report a bug, Create Configuration report
And then do:
db configuration show
Remove anything sensitive like passwords and public IPs.
You might want to put this on somewhere like pastebin as it will likely be long.
If you want people here to help you then you need to start helping them.