Thunderbird Mail "add Security Exception"

[ProDave]

New laptop, Windoze 8.1

I quickly gave up getting the windoze mail program working, it didn't seem interested in anything other than hotmail etc.

So I downloaded Thunderbird as that's been working well on the Linux laptop. Downloaded version 38.3.0

It's working but with one problem:

Every time it tries to collect mail, it brings up an "Add Security Exception" dialogue box.

It says:

"You are about to overide how Thunderbird identifies this site. Legitimate banks, stores and other public sites will not ask you to do this.

Location: Mail.tesco.net143

Certificate Status:

This site attempts to identify itself with invalid information

Wrong Site:

The certificate belongs to a different site which could mean that someone is trying to impersonate this site

Unknown identity:

The certificate is not trusted because it hasn't been verified as issued by a trusted authority using a secure signature"

Clicking the "confirm security exception" button gets it to collect emails from the server.

But in spite of ticking the "permanently store this exception" box it still asks this every time.

So what does it mean?

Is there really a problem I should be worried about?

How do I stop this message coming up every time it tries to collect mail?

 

[ProDave]

Well I sat the two laptops side by side and compared settings.

The Ubuntu one had security set to "none" whereas the windoze one was trying to use some security (I forget which one)

So I have just set it to none as well and all is well.

 

[Lurch]

You're probably better off manually adding the exception rather than turning security off.