Hey there,

I'm facing a conundrum with SSL for a mail domain on my Hetzner VPS, where ISPManager is keeping things in check. I've got multiple sites, each with its own mail domain, rocking DKIM, DMARC, and SSL. I scored a wildcard SSL cert for 'sats', supposedly fitting for mail domains as I've got DNS records for smtp.domain., pop.domain., and mail.domain*. Upon receiving the cert, I was prompted to add a token to the DNS records, which I duly did via 2ip, along with DKIM.

However, when I'm trying to send mail, my mailer's throwing a hissy fit, claiming there's no certificate for smtp.domain.*. It's all "that cert's for another site, namely static.XX.xхx.xхx.xхx.clients.your-server.de", which is the IP address Hetzner graced me with.

So, I'm wondering, how can I get my mail sending to Gmail to play nice? Other addresses seem chill with it.

Any tech-savvy insights on tinkering with the DNS records or SSL configuration to make it rain emails to Gmail? Much appreciated!

It sounds like you're dealing with a classic SSL mismatch issue. The wildcard SSL cert you obtained is indeed for sats, but your mailer is complaining about the certificate not being valid for smtp.domain.*. This is because the cert is tied to the IP address static.XX.xхx.xхx.xхx.clients.your-server.de, which is not the same as your mail domain.

To get your mail sending to Gmail to play nice, I'd recommend creating a separate SSL cert for each mail domain, rather than relying on the wildcard cert. This will ensure that each mail domain has its own unique cert that matches the DNS records. You can then update the SSL configuration in ISPManager to use the new certs.
Double-check that your DNS records are correctly configured for each mail domain, including the smtp, pop, and mail subdomains. Make sure the records are pointing to the correct IP address and that the SSL cert is properly installed.

We're trying to nail down the server's moniker here, yeah? It's probably not just the plain old PTR record for the IP, but we're also looking for the full-blown hostname. So, let's not just stop at the easy stuff, let's dig deep and find that primary identifier, got it? Over and out.

Likely, the root cause of the problem lies in the misconfiguration of the mail server's domain (hostname) and its corresponding PTR record. Gmail has recently ramped up its scrutiny of such settings.

Regarding the certificate, it serves as a crucial security layer for encrypting data transmitted between the client and your server, as well as when Gmail fetches emails from your server. In this context, the certificate is essential for establishing a trusted connection. However, it appears that the certificate was issued for an incorrect domain (or domains), resulting in a name mismatch error message.

In this scenario, it's essential to revisit the certificate issuance process and ensure that it aligns with the correct domain(s) to resolve the discrepancy.