I have no real knowledge about this stuff so I figured I'd ask here for some answers.

So I started to get this "Security Certificate not issued by a valid authority" error when using my email client yesterday when attempting to connect to the STMP server of my ISP. I haven't changed anything in my Android phone or my desktop and both are giving me this grief.

When I look at the certificate details it says its from VeriSign but doesn't seem to be authentic.

What causes this error? What should I do besides complain to my ISP about it?

I was asked for additional info so I manually copied it over you.

My ISP is saying that 90% of the time its time stamp problems and I should check my time on my end...its a friggin' cell phone that gets its time from the network so I can't see that as being the issue.

I was having this issue with both my desktop and my phone, now the desktop works again but the phone is still giving error messages.

This certificate is not from a trusted authority.

Issued to:

Common name: mail.shaw.ca

Organization: Shaw Cablesystems G.P.

Organizational unit: Engineering

Issued by:

Common name: VeriSign 3 Secure Server CA -G3

Organization: VeriSign, Inc.

Organizational unit: VeriSign Trust Network


Issued on: 2013-11-11 16:00:00-0800

Expires on: 2014-11-19 15:59:59-0800

2 Answers 2


You could try to access the link from a browser and check the certificate details( like in firefox: Edit -> Preferences -> Advanced -> View Certificates ). Enusre that various fields like issue to and dates are correct. Please post the details if that is feasible.Also which email client are you using ?

Since "Security Certificate not issued by a valid authority" is exactly what it means and there are no changes done on your part, go ahead and mail to your ISP already.

  • Use Thunderbird on the desktop and whatever the default email is on the Android HTC. The desktop client has started to work again. Commented Dec 15, 2013 at 18:41
  • Chef, did you try to find out if there are actually any time differences in the Desktop and your phone[adb shell date]. Did you try clearing the cache and force stopping the app in the android device and logging back again? Like Jinyang said the tech support staffs are not actual engineers so keep trying stuff.
    – ark1n
    Commented Dec 16, 2013 at 11:13
  • Time is the same on both devices. From what I've read online chances are the Intermediate Certificate(s) are not properly installed on their servers but Desktop email clients will be smart about the whole thing and look at the certificate and somehow work out that it is valid due to where its was issued from. Kinda foggy on the details. However Android Phones are stupid this way and need to be shown the exact path to the Root CA. Anyway, now the Help Desk Fluff are trying to get ME to contact VeriSign about the problem. WTF?! Commented Dec 16, 2013 at 19:52

Certificate problems may indicate a MiTM attack. Maybe you should call your ISP before you continue using the webmail. Also, what do you mean when you say the cert doesn't seem to be authentic? Is it an expired cert or wrong common name?

  • By not being authentic I mean that is what the email client is telling me. To be truthful I have no idea what a proper common name would be. Not knowing how someone fakes these things, I've assumed that a counterfeit certificate would look very much like a real one wouldn't it? The real difference would be in the long numeric keys that are attached to them? Commented Dec 15, 2013 at 18:46
  • Since its working on your desktop now, then it could be some server misconfiguration on their end. Give them some time to fix it before you continue using the webmail :)
    – jingyang
    Commented Dec 16, 2013 at 1:44
  • They're saying its my fault now. I'm expected to clear my cache a few times and see if my phone provider has done any updates lately. The really funny thing was the link to the information they found about the problem and how its clearly stated that its an ISP misconfiguration issue. I hate dealing with the first line of tech support. Commented Dec 16, 2013 at 9:11
  • I couldn't agree with you more. Usually the tech support staffs are not actual engineers and can't really help you much other than giving you excuses.
    – jingyang
    Commented Dec 16, 2013 at 9:18

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