Duplication of old e-mails in old POP3 Local Folders

I originally installed eM Client about 3 weeks ago on my old Satellite Pro M70 / WinXPSP3 laptop, and then imported all my email folders (dbx) from Outlook Express .

I subsequently (about 1 week later) also installed eM Client on my new HP Probook 450 G1 / Win 8 Pro laptop, and transferred the eM Client data files from the old laptop, by restoring the backup of the eM Client data files made on the Sat Pro M70 laptop, to the eM Client on the new HP ProBook 450 G1 laptop.

Today, on the new laptop, I noticed the duplication very old e-mail messages (up to about 10 yrs old) in many of the old Local Folders  of my POP3 e-mail account, and also some of the newer e-mails messages in newer Local folders.

I checked the e-mail Folders in my POP3 account on my ISP’s webpage, and there are only about 5 very recent e-mail messages in the Inbox folder, so the duplicates cannot be coming from there.

It would appear that duplication of many of the e-mail messages had taken place during &/or after the  importing of e-mail from Outlook Express 6 to eM Client on the Old Sat Pro M70, because the duplicate e-mails do NOT show up in the respective Outlook Express POP3 account e-mail folders, but do show up in eM Client on the Old Sat Pro M70 laptop.

I have tried restoring 3 different eM Client data file backups, and have also re-installed eM Client twice on the new HP ProBook 450 G1 laptop, but  it makes no difference; the duplicate e-mails are still there.

I hope that this is not an on-going duplication process.

I would greatly appreciate if anyone could tell me what could be causing this problem, and how to resolve it.

Thank you very much


Hi, if this is an issue that occurs only with the imported emails you can try using the deduplicator feature in Tools > Deduplicator.

I hope that solves the issue for you,
thank you,

Hi Paul,  

Thank you very much for your response, info & suggestion re: the de-duplicator.    
Please excuse this very long & detailed reply post,.
1. The De-Duplicator :
How does the de-duplicator work, and where can I find more information about it on the eM Client website ?
Can individual folders be selected for de-duplication, or does it just do them all ?
1. Duplication of e-mails in the very old “Karl” Folder of my Local Folders of my ISP POP3 e-mail Account :
I just checked one of the folders (Karl) which contains 191 unique messages which appears to have been duplicated in eM Client AFTER the importation e-mail data files from Outlook Express 6, so that there are now 2 x 191 = 382 e-mails in eM Client’s Karl folder on my Old Satellite Pro PM70 Laptop, which have been backed-up & restored to my new HP Probook  450 G1 laptop, with the rest of eM Client data files.

The duplicate e-mails are of ALL e-mails that were sent by me, & of ALL e-mails that were received by me, over the period July 1999 to Feb 2014, that is before the installation of eM Client on my old Sat Pro M70 laptop on the 7 Apr 2014.
2. Possible Mechanisms for the Duplication Process :  
I suppose that there are at least 2 possible mechanisms for the duplication process :
Mechanism #1 :  If all the sent & received e-mail dating back to July 1999 are still stored on my ISP’s  Outgoing (SMTP) & Incoming (POP3) e-mail servers, then it might be possible that servers downloaded the sent & received e-mails to eM Client, perhaps as a result of automatically detecting eM Client as the new desktop e-mail client replacing OE6, or as result of an inadvertent / unintended request from eM Client (in other words a bug in eM Client).
Mechanism #2 : eM Client of its own accord (i.e.  independently of my ISP’s, Outgoing & Incoming e-mail servers) has duplicated all the e-mails in the Karl folder, which again would have to be a bug in eM Client.
3. Duplication of e-mails in the newer “Laptops_HP_LealCI” Folder of my Local Folders of my ISP POP3 e-mail Account :
In a newer folder named “Laptops_HP_LealCI”, which was created on the 14 March 2014, only the 31 e-mails that were sent & received BEFORE the installation of eM Client on the 7 April 2014, have been duplicated (i.e. sent & received between the 14 March 2014 & the 7 April 2014).
The 31 e-mails that were sent and received AFTER the installation of eM Client on my Old Sat Pro M70 laptop have NOT (so far) been duplicated.
Conclusion : This would tend to support duplication mechanism # 1.
If this is correct, then the question is how can it be prevented ?
for example :
- Is there a bug in eM Client that can be fixed, that has inadvertently signaled to my ISP’s SMTP & POP3 servers to download to eM Client, all e-mails that were sent & received, prior to the switch from OE6 to eM Client ?
- Can eM Client be programmed to signal to my ISP’s SMTP & POP3 Servers, NOT to download the sent & received e-mails stored PRIOR to the replacement of OE6 by eM Client ?
4. Evidence of an Active On-Going e-mail Duplication Process :
It would appear that the duplication of sent & received e-mails is an active on-going process, because the Size of the EM Client Folder in the path
“This PC>Windows(C:)>Users>Alan>(User-Me)>AppData>Roaming>EM Client”,
has increased by 5.21 MB (5,212,014 bytes), from 2.646 GB (2,646,643,992 bytes) at 9:03 pm on Tues 22 Apr 2014, to 2.651 GB (2,651,856,006 bytes) at 6:23 am on 24 Apr 2014 (today), whereas during this period I have sent and received about 17 e-mails, which gives an increase the size of of the eM Client Folder of 306.59 KB (306,589 bytes) per e-mail sent & received over this period.
This is unlikely without the duplication my ISP POP3 account e-mails by an active, on going duplication as per Mechanism # 1.
At this rate of duplication, the eM Client data file could conceivably increase by as much as 1.90 GB over a 1 year period from the current 2.651 GB, to 4.55 GB (a 72% increase) assuming the same daily usage of eM Client as for the period Tues 22 Apr 2014 , 9:03 pm to 24 Apr 2014, 6:23 am.
5. How to Proceed from here onwards, assuming an active on-going e-mail duplication process of e-mails sent & received (prior to the switch fro OE6 to eM Client) in the Local Folders my ISP POP3 e-mail account.
The question for me now, is how to proceed from here, with active on-going e-mail duplication occurring  in my ISP e-mail account, and with no programming “fix” for it ?

  • I suppose I could do periodic de-duplications of the duplicate e-mails, in the hope that they do not re-occur.
  • I could de-activate my ISP e-mail account, perhaps by simply disabling or deleting the account in eM Client, and the de-duplicate the duplicate e-mails, and use only my outlook.com IMAP account. 
    This of course would mean advising my “current active” contacts (at least ) of the change in my e-mail address, a tedious task. Of course some e-mails might slip through to my de-activated e-mail account, but I suppose I could check it periodically on the ISP e-mail account web page for any incoming e-mails, and forward them to my outlook.com e-mail account.
    Do you have any other suggestions ?
    If you prefer , you can e-mail at the e-mail address that I used for registering in the eM Client forums.
    Thank you for your kind attention & patience.

Hi Alan, I believe the duplication is not an ongoing process as it’s a matter of imported emails mostly, and if it’s not happening with new emails.
Can you maybe make a screenshot of the folder with duplicated messages?

You can chose the folders for the deduplicator, even local folders. It’s pretty easy, try it I think it should solve the issue.

Thank you,

Hi Paul. I have already carried out the deduplication on all folders, both for my POP3 e-mail account which had about 25%  duplication, and my outlook.com e-mail account which also had a few duplications, which I think were “Forwarded as Originals”.

In my POP3 account web page, I just tried to set up mail redirection of mail sent to it, to my outlook.com account,

I then tried to test it by sending a test e-mail from my outlook.com account in eM Client to my POP3 account in order to see if it would be redirected back to my Outlook.com account, with the redirection text I had composed, 
However when I tried to send the test e-mail from my outlook.com in eM Client, instead of the Test message going into the Outbox of my outlook.com account, it went into the Outbox of my POP3 account, even though the “From” field has my outlook.com e-mail address.

When i tried to send it I got an eM Client error message which says “an error has occurred Sending email failed with an error: The remote server returned an error (400) Bad Request”.

The Error log confirms that the email was trying to be sent from my outlook.com account.

I have have also tried canceling the email redirection in my POP3 email account website in order to eliminate it as a factor.  I do not know if the cancellation was successful. Will have to phone my POP3 account ISP tomorrow to check.

Do you have any idea what is causing this problem and how to resolve it ?

I did a backups of the eM Client  data file before, during and after the deduplication process, which I had done in several steps.  Can I simply try doing Restores of before &  after deduplication backups, in order to to see whether that creates & resolves the problem ?

To summarise the problem : E-mails sent from my POP3 account are being received by my outlook.com account in eM client, but when I try to send emails from my outlook.com account, it moves the POP3 account Outbox instead of the Outlook.com outbox, and I get the error message when  I try to send it.

Note:Just prior to setting up the redirection option in my POP3 account webpage, I did in fact successfully send an e-mail to someone from my outlook.com account in eM Client, which tends to suggest that trying to setup the redirection is probably the cause, although I cant understand why.

The text I used for the redirection in my POP3 account webpage was :

“The e-mail message you have just sent to me, CANNOT be received at my old e-mail address, which you have used to send it to.Please resend your e-mail to my new e-mail address xxxxxxxx@outlook.com”.

I ticked 3 boxes : “enable email redirection”, “preserve to /cc fields” & “keep a copy of messages”, which I have since unticked, and the pressed the “Update” & “Reset” buttons in order to try to cancel the redirection.

Thank you for any help you can offer in resolving this problem.


Paul, Further to the above post, the size of the eM Client Data file has changed from 2,057,109,487 bytes & 59 files before the POP3 account redirection setup attempt, to 2053,640,707 bytes, & 65 files after the POP3 account redirection setup attempt, that is a decrease of -3,4687,780 bytes & an increase of 6 files.

Paul, I can send you a screen capture of the EM Client data files after the POP3 cancelled redirection attempt, if that would help ? But you would have to advise me how to do it.

Paul - a correction to 2nd above e-mail: : a decrease of -3,468,780 bytes

Update - I just tried to re-check my POP3 account on my ISP email account webpage, and was unable to access it, but there was a message which says “Network IO suspended”, which is presumably as a result of my failed attempts to set up & then cancel the email redirection option. 
They must think that someone was trying to hack into it, because the redirection attempts occurred between 1:00 am & 3:00 am. It is 6.11 am now, and will have wait until 9:00am to phone them to sort it out, so that I can use the account normally again, hopefully.

If that is successful, then I would propose to restore the eM Client data file backup (backup_201404241622.zip), that I made just after the deduplication of emails in all eM Client Folders. Can I just restore it directly over the current eM Client data files ?
Do you that this would resolve the outlook.com problem ? 


Hi Alan, I suggest working the settings out with your ISP mail service provider, there’s obviously some issue with connecting to that account.
I believe they should advise on the redirection setup as well.

You can, use the backup as you suggested, over your current data, that should cause no further issues.
Just a note, the eM Client data folder will be changing its size, as you receive new emails, and there’s a lot of activity in the application, you don’t have to report on it’s size, doesn’t really affect any of your issues.

Please check back with me once you resolve the issue with the ISP account with your provider.

Thank you,

Hi Paul, Thanks for your quick response.  
I spoke to my ISP support, but their e-mail support staff have a 24 - 48 hrs response time, so if I’m very lucky they will phone me tomorrow (Sat) to sort it out; otherwise Monday.

Was able to get back into my POP3 account webpage, but there was no observable change in the status of redirection option, so there is probably not much point in trying the eM data file restore at this time.

There is no info on the redirection set up & process on the ISP’s web site. My objective would be to disable the POP3 account in eM Client, but not at my ISP, and instead have all new e-mail received by the POP3 account  redirected to my outlook.com account.

This should enable to me to advise my active contacts on an as need basis, of the change in my e-mail address to outlook.com, & would hopefully also avoid the duplication of old e-mail, unless of course the duplicates get redirected to my outlook.com account instead. If that happens, I will terminate the POP3 account.

Hi again Alan, I believe the best setup would be setting up the redirection properly on your server and disabling that account in eM Client completely (as all your mail will be redirected to the other account automatically). Since you’ve backed up and exported all your mails from that account and imported it into local folders (or your new account), this should be the best working setup.

However it’s quite depending on the redirection setup.

I hope the duplication issue, was solved with the deduplicator feature, there might have been a bug during the import, but it shouldn’t be duplicated during standard use of the email again.

Thank you, hope this helps, let me know how it went with the ISP’s support,

Hi Paul

Just thought I would update you with regard to the email redirection problem that I created in my ISP POP3 email account, which had corrupted the eM Client data files in the eM Client Pro version installed on my new HP Probook 450 G1 /Windows 8.1 Pro Notebook PC.

After my ISP, at my request, eliminated the erroneous email redirection attempt (to redirect emails from my ISP POP3 email account to my outlook.com web email account), I restored eM Client from the most recent, de-duplicated, & fully up-to-date backup, and consequently the “eM Client data file corruption problem” was resolved.

However, I did not attempt again to set up the redirection of emails from my ISP POP3 email account to my outlook.com email account, because I did not feel like tempting fate again at this point in time, when everything has been running smoothly with the “eM Client Pro version” on my new HP Probook 450 G1 Notebook, which is synchronised with the “eM Client licensed free version” on my old Satellite Pro M70 laptop.

I have since had to return my new HP Probook 450 G1 notebook to the HP Supplier, either for repair or replacement, due to a touchpad “intermittent unresponsiveness problem”, plus a “suspected developing Hard Drive problem” (intermittent soft-clicking noise). Consequently I am writing this reply post from old Sat Pro M70 laptop (with the eM Client licensed free version).

When my HP ProBook 450 G1 Notebook (original repaired unit, or replacement unit) is returned from the HP Supplier, is there any special procedure that I would have to follow to re-install eM Client Pro version ?



Hi Alan, thank you for the update. Well, if you’ve already send your computer to HP, there’s not much else to do to avoid any complications, however when you receive your repaired or replacement unit, just use the license key you already have for activation and it should work fine.

However sometimes when you don’t deactivate the previous license there might be some issues, but let’s not get ahead of ourselves, I’m sure it will work fine when it arrives and if not, let us know, there’ll be quite an easy solution for that, but remember when you want to switch your license to a different computer, it’s better to deactivate the license on the previous instance of eM client.


Hi Paul,
Thanks for your reply & advice.
No, I am afraid I did not deactivate the eM Client Pro license before uninstalling it. Will let you know if I have any problem activating it again.