Disable Outlook Certificate Warning

Hi Experts,

I'm receiving a warning each time I start Outlook, regarding the validity of a certificate on my mail server, which is run by my webhost.  The error message is:
   "The server you are connecting to is using a security certificate that cannot be verified.
    The target principal name is incorrect.
    Do you want to continue using this certificate?"

Certificate Warning messageIf I click "Yes", then all is fine (emailing works and no more warnings) until next time I stop & restart Outlook.

If I click "View Certificate", I can see these 3 tabs of information:
Certificate General tabCertificate Details tabCertificate Certification tabI started getting this warning after changing to an ISP which required outgoing emails to use SSL, so I had to change the SMTP port from 25 to 465 and select SSL encryption.
(Also note that our webhost's outgoing mail server requires authentication.)

I'm using Outlook 2007 (on WinXP), but I also need to help someone who's using Outlook 2013 (on Win7) and Windows Mail (on Win7) with the same problem.

I tried installing the certificate on the Outlook 2013 machine, via the "View Certificate" page, and it seemed to install OK, but I still had the problem.

I've seen a few web pages which talk about similar problems, but haven't seen any nice solutions to this exact issue yet.


Q1. Is this warning occurring because the certificate is issued to *.abstractdns.com (which is owned by our webhost), and I have a totally different domain name for my email (let's say my address is: me@mydomain.com)?

Q2. How can I avoid this error message in Outlook 2007/2013 without having to buy a security certificate for our domain?  Do I have to edit the registry as in "Method 4", here: http://support.microsoft.com/en-us/kb/2783881 ?  I tried that with Office 2007 on WinXP and it didn't work.  I also tried http://support.microsoft.com/en-us/kb/276597 with Office 2007 on WinXP and it didn't work either.

Q3. How about Windows Mail?

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Zacharia KurianAdministrator- Data Center & NetworkCommented:
Have you gone through the below link, which was posted on EE?


tel2Author Commented:
Thanks Zac.

No I haven't, but it might take me a couple of hours to do so.  Looks as if that situation is significantly different from mine, so if anyone else can point to something specific for me to check/change, that could save me a lot of time going down that (possibly inappropriate) track.
Zacharia KurianAdministrator- Data Center & NetworkCommented:
regarding the validity of a certificate on my mail server, which is run by my webhost

Ok. have you contacted your webhost admin about this issue? or are you the one who is managing the webhost?


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tel2Author Commented:
I haven't contacted them yet, Zac, but was intending to if I get no joy elsewhere.

I know they might be able to help me, but they probably consider that it's not really their responsibility, because I expect that they would say that their SMTP server works fine for people who either:
- Use port 25 without SSL
- Get their own SSL certificate.
tel2Author Commented:
Hi Zac,

Having not had anymore suggestions here, I contacted the webhost and they said I could try changing my POP3 & SMTP mail servers from:
and it looks as if that may have resolved the issue.  I'll try it on 2 more PCs before I close this question.

So, it looks as if it was quite appropriate that I raise this with them, so your suggestion was a good one.

tel2Author Commented:
Hi again Zac,

I've made that change on all 3 PCs now, and it seems to be working on all of them (i.e. no more warnings even after stopping/starting Outlook 2007/2013 / Windows Mail), so thanks for your advice.  Seems I should have asked the webhost first, in this case.

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