droogiee — understood. Since you already tried the hostname, domain, mail subdomain, direct IP, ports
25,
465,
587, TLS on/off, and a simple password, I would stop random combinations now. The next step is to
prove exactly where the session fails.
The key point remains:
Yahoo/GMX working first try proves the printer’s SMTP feature works. Your host may still be compatible with your cameras, but incompatible with the HP printer’s SMTP/TLS/auth behavior.
Important: using the IP address is not a valid TLS test
If TLS/SSL is enabled, using the host’s raw IP address can fail because the certificate is usually issued to a hostname, not the IP.
For example, this can fail:
Code:
SMTP server: 123.123.123.123
Port: 465
TLS: On
Because the certificate may be for:
server123.hostingprovider.com
or:
mail.yourdomain.com
So for TLS testing, use the
exact SMTP hostname that matches the certificate.
What I think is happening
Your printer likely reaches the hosting provider’s SMTP service, then fails during one of these stages:
- TLS handshake
- certificate validation
- SMTP AUTH method
- server policy/security filtering
- server closes the connection before normal mail logging
- host only checked sent-mail logs, not connection/reject/firewall logs
That would explain why they say “we see nothing.”
Next step 1: test the host from a Windows PC
From a Windows PC on the
same network as the printer, open PowerShell and run:
Test-NetConnection mail.yourdomain.com -Port 465
Then:
Test-NetConnection mail.yourdomain.com -Port 587
If either says:
TcpTestSucceeded : True
then your network can reach the host on that port.
If it says
False, something is blocking the connection before the printer even gets a chance.
Next step 2: test the SSL certificate
If you have OpenSSL installed, run:
openssl s_client -connect mail.yourdomain.com:465 -servername mail.yourdomain.com
Look for this near the bottom:
Verify return code: 0 (ok)
If you see a certificate mismatch, expired certificate, incomplete chain, or handshake failure, that is strong evidence for the host.
Also test the host’s real server name if they provide one:
openssl s_client -connect server123.hostingprovider.com:465 -servername server123.hostingprovider.com
Next step 3: ask the host to live-monitor the logs
Do not ask them generally, “do you see anything?” Ask them to watch while you test.
Send them this:
Code:
Please live-monitor SMTP connection, TLS, authentication, reject, and firewall logs while I test from my HP OfficeJet Pro 9010.
The printer works immediately with GMX/Yahoo using port 465 with TLS, so the printer's SMTP feature works.
Please do not only check sent-mail logs. If the failure happens during TCP connect, TLS negotiation, certificate validation, SMTP banner, or AUTH, it may never appear as a sent message.
Test details:
Public IP: x.x.x.x
SMTP host: mail.mydomain.com
Port: 465
Encryption: SSL/TLS enabled
Username: [email][email protected][/email]
From address: [email][email protected][/email]
Test time: I will test while you are watching.
Ask them to check specifically:
Code:
Exim/Postfix SMTP logs
Exim reject logs
Dovecot/auth logs
CSF/LFD firewall logs
cPHulk logs
Imunify/security logs
TLS handshake failures
SMTP AUTH failures
blocked IP events
Next step 4: ask for the exact SSL SMTP hostname
Ask them this exact question:
What exact SMTP hostname should I use on port 465 so the SSL certificate name matches the server?
This matters.
mail.yourdomain.com may point to the server, but the cert may actually belong to the hosting server name.
Next step 5: ask whether they support HP-compatible auth
Ask them:
Does your SMTP server allow AUTH LOGIN and AUTH PLAIN over SSL/TLS on port 465?
Many printers and scanners use older/simple SMTP authentication methods. If the host only supports methods the HP does not use, it will fail even though normal mail clients or cameras work.
Best printer-side settings to use for the next test
Use one clean test only:
Code:
SMTP server: exact SSL-valid hostname from host
Port: 465
TLS/SSL: enabled
Username: full email address
Password: mailbox password
From address: same full email address
Authentication: enabled
Do not use the IP address for this test.
If the host still says “nothing”
Then ask them this:
If you see no connection at all from my public IP during a live test, can you confirm whether your firewall or upstream provider is dropping the connection before it reaches the mail daemon?
Because if the printer gives a different error for bogus hosts/ports than for the real host/port, something is probably responding or dropping at the host side.
Practical workaround if they cannot fix it
If your host refuses or cannot identify the failure, use one of these:
- Keep using GMX/Yahoo for printer alerts.
- Use a dedicated SMTP relay such as SMTP2GO, Mailgun, SendGrid, etc.
- Set up a local SMTP relay on a PC/NAS/server and have it forward through your domain account.
- Create a separate mailbox at the host just for the printer and ask them to whitelist your home public IP.
Bottom line
At this point, you have done enough printer-side testing. The next useful move is not more port combinations — it is a
live log check by the host while you press “test” on the printer.
Your strongest argument is:
The HP sends successfully through GMX/Yahoo on port 465 with TLS. Therefore the printer can send SMTP. The failure is specific to the hosting provider’s SMTP service, certificate, authentication method, or security filtering.
