What is the exact error message? Can you post a screenshot? Is your anti-virus software intercepting your secure connection to the server?

I'll take a screen shot next time the error appears, I just cleared it. Its the standard window for this, I have seen it in the past but this is the first time it has been so persistent, usually you just have to click ok or whatever and its good from then on.

I don't believe there is any anti-virus software active on this computer, just the basic Windows 7 stuff.

Thanks.

That sounds mighty like avast anti virus, are you sure?

I just checked the list of installed programs and Avast is certainly not on there, nor did I see anything else in there that appeared to be anti-virus software.

Thanks.

You are aware that statistically a computer with no anti virus will be infected with something in about 90 minutes I assume.

I suggest you run an anti virus scan. Malware loves setting into the TCP stack and intercepting certificates. As you have no protection then it is a real probability.

I was not aware of that, I own Macs for my own personal computing where it is not as much of an issue, though I must say I never ran anti-virus when I owned my own PCs either and never had issues with that. I have little control over what software is on this computer, it belongs to my work, but we have no IT department or similar services available to us, so we are on our own as far as repairs go.

Back to the email issue, what steps do you suggest I take now? Shockingly the error hasn't reappeared as quickly as it has been.

Thanks.

https://support.mozilla.org/en-US/questions/1053126#answer-706847

You wanted to post a screenshot.

Here is a screen shot of the error. If I click "Get Certificate" nothing happens. If I click "Confirm Security Exception" the box goes away but comes back after anywhere from 10 to 30 minutes.

I ran Malwarebytes scan tool and it corrected a couple things but indicated they weren't serious.

Thanks for any further suggestions.

What is the point obfuscating the server location in your screenshot?

Inspect the presented certificate (see the attached screenshot for instructions). Who is the issuer of the certificate you get? You may also post a screenshot of the Certificate Viewer window.

I didn't know if any of that info was sensitive, I don't know a lot about this stuff. I see the same in the screenshot you posted, so I must not be too crazy.

Here is a screenshot of the Certificate Viewer window.

The certificate looks legitimate. Can you also post the obfuscated part in the first screenshot?

In the Certificate Viewer window, can you select the 'Details' tab and post a screenshot of that as well?

That certificate is for the server aplus.net and it's sub domains, such a mail.aplus.net or forum.aplus.net

While your information may be obfuscated the length of that domain does not look like aplus. and it looks to me like a com not a net.

Perhaps you need to talk to the people issuing that certificate.

Please confirm that your user account on your computer is an administrator one.

No, it is definitely not aplus, it is my company's name as used for our .com domain, and then a port 110 on the end.

I am an Administrator on this computer.

You mean talk to aplus? I wonder if they are our hosting provider.

I'll add screen shots later, I got 6-7 of the errors in one shot in the middle of the day today, but aside from that the certificate errors were scarce. I'll have to wait for it to happen again before I can capture it.

There are two other people here using the same email system that has not changed in years, neither are having a similar issue but both of them are using Outlook.

Thanks

I wonder if they are our hosting provider.

I'd wonder about that too. Please confirm.

The hosting provider for aplus.com is Google. What is the mail server name your trying to connect to.

Try the following, just to see if they work.

POP mail server mail.aplus.comt port 995 with SSL and 993 without SSL

The server mail.aplus.com responds to ping requests so a connection should be possible.

I have confirmed aplus is our hosting provider.

I tried the settings suggested and I could not receive email, though I am not 100% sure I did it correctly.

Thanks

So far we've confirmed the cert is legitimate. Can you click the 'Details' tab in the 'Certificate Viewer' window and post a screenshot as well? We're looking for the certificate chain. It seems one cert in the chain is missing in your case, so Thunderbird can't verify the entire chain.

I'm getting the same error. I've used Thunderbird for 9 years. Currently use it to manage 4 addresses and it is happening for each of the addresses. I tried to get a screen shot before posting but can't seem to get it to happen right now.

My company email(x3) server settings are Incoming imap.googlemail.com port 993 Outgoing smtp.googlemail.com port 465 Security SSL/TSL Normal Password 2 step is not enabled on GMail for our domain

My personal email(x1) server settings are Incoming secure39.webhostinghub.com port 993 Outgoing secure39.webhostinghub.com port 465 Security SSL/TSL Normal Password

I do have avast installed avast! Mail Scanner Certificate Name Server secure39.webhostinghub.com secure39.webhostinghub.com; 465 secure39.webhostinghub.com secure39.webhostinghub.com; 993 imap.googlemail.com imap.googlemail.com; 993 Lifetime = Permanent (for all) Expires on secure39 = 02/23/2017 and googlemail = 06/22/2015

Oh missed adding the certificate for smtp.googlemail.com smtp.googlemail.com;465

What part of the certificate details are you looking for. I can only screen shot one section/item at a time

I'd like to see the 'Details' tab in the 'Certificate Viewer' window.