In article 20071024170332.GA9826@bit.office.eurotux.com, Luciano Rocha strange@nsk.no-ip.org wrote:
On Wed, Oct 24, 2007 at 11:46:34AM -0500, Chuck Campbell wrote:
I see these messages every time fetchmail pops my mail. I don't understand what certificates it is talking about, or how to straighten this out.
A certificate identifies the server, i.e., the client gets a piece of information about the server that can be used to start a private conversation. The certificate must be signed by an entity, that you trust.
fetchmail: Server CommonName mismatch: localhost != mail.mydomain.com
The certificate was issued for the server: 'localhost', but you're connecting to 'mail.mydomain.com'. This could be a man-in-the-middle attack.
Or it could be a poorly set up mail server.
fetchmail: Server certificate verification error: self signed certificate
The certificate is signed by itself, not by an external entity that you trust. You can't be sure you're talking with the correct server.
fetchmail: Server certificate verification error: certificate has expired
Every certificate has a validity (start and end date when the certificate is valid). Yours has expired.
Actually, it is not "your" certifiate. It is the certificate installed on the mail server. It looks like the administrator of your mail server has set it up with a test certificate issued to "localhost", signed by itself, and which has now expired. They should instead purchase a validated certificate from a certification authority.
What do I need to read up on to understand this and find a fix?
It's not something you can fix, except by getting your mail hosting from another provider, or persuading your current provider to get a proper certificate.
Cheers Tony