Thunderbird email certificates


When sending emails out using Thunderbird email client, customers are getting the following error. "your certificate contains the same serial number as another certificate issued by the certificate authority. Please get a new certificate containing a unique serial number"


To resolve this issue, you will need to delete a certificate for your outgoing mail server found within your thunderbird application.

Open Thunderbird then go to: Tools -> Options -> Privacy -> Security -> View Certificates -> Web Sites, then delete the certificate listed for your website/domain or the WESH server name. You may then need to close and reopen Thunderbird for this to work.

  • 44 Users Found This Useful

Was this answer helpful?

Related Articles

AOL and "Report As Spam"

Those who use AOL as an ISP will be aware that they have their own email application integrated...

Duplicate Blackberry emails received

If you have a Blackberry and are receiving multiple duplicate emails, this seems to be caused...

Can I operate email mailing lists?

We do allow the use of email mailing lists but there are some conditions in place. Firstly, we...

Email not getting through to

My emails are not getting through to address's? This is due to a new feature put in...

Outlook not receiving mail

What is the Problem? Any emails I send to a free email address provided by Microsoft never...