Hi, I’m using Thunderbird on Windows and recently ran into a certificate warning that I can’t safely interpret, even after searching the web and using AI tools (which gave me inconsistent answers). Thunderbird tries to connect to the iCloud contacts server p123-contacts.icloud.com (CardDAV). When it does, I get a “wrong site” certificate error. When I click “View certificate”, Thunderbird shows a valid certificate, but not for Apple/iCloud – it’s for login.kraftcom.de (issued by DigiCert / GeoTrust TLS RSA CA G1). I did not accept the exception. From what I can see online, p123-contacts.icloud.com is a legitimate Apple domain, but it is also mentioned in some phishing / scareware contexts, which makes me even more unsure how to interpret this combination (Apple host + Kraftcom certificate). I’m also not sure whether this is simply a captive-portal / ISP login interception effect or something that should worry the wider community. My questions: Is this behavior expected in any scenario, or does it indicate a misconfiguration / MITM situation that Thunderbird should treat as a serious security issue? Is there anything I should check or change on my side (Thunderbird config, network, ISP, certificates)? Is there any additional diagnostic information I can provide (logs, screenshots) that would help you assess whether this is a Thunderbird issue or a network/ISP issue? I specifically did not confirm the certificate exception and I would like to keep my setup secure, but I also want to make sure the community is aware if this is a broader problem. Thanks in advance for any guidance