" If you are netsecdesign.com, ssllabs says your cert has issues. Not that this may be your problem, but I would fix that first."
This cert is not the same cert or the same server or the same IP address as my postfix SMTP gateway. The postfix SMTP gateway uses a self-signed certificate. On 6/21/19, 10:42 PM, "owner-postfix-us...@postfix.org on behalf of Viktor Dukhovni" <owner-postfix-us...@postfix.org on behalf of postfix-us...@dukhovni.org> wrote: > On Jun 22, 2019, at 1:12 AM, lists <li...@lazygranch.com> wrote: > > If you are netsecdesign.com, ssllabs says your cert has issues. Not that this may be your problem, but I would fix that first. The certificate is past its nominal expiration, but perhaps more importantly its "Basic Key Usage" field says: X509v3 Key Usage: Certificate Sign which does not include digitalSignature, and that's most likely the issue. A more appropriate certificate is more likely to work. Gmail IIRC enforces more TLS hygiene when TLSv1.3 is negotiated. -- Viktor.