SMTP Delivery Problems

I’ve been struggling with settings up SMTP to work, I really hope someone can help me out with my sccenario. So let’s say that my discourse forum is located at and my mail is at The discourse is on a Google Cloud VM, the Mail server is on a different host (It’s just a simple webhost with cPanel)

My Settings are the following:

SMTP address:
SMTP port: 26
SMTP username:
SMTP password: mailpassword

With these settings, I get an error that my host name does not match the certificate, and mails do not get delivered.
If i use DISCOURSE_SMTP_OPENSSL_VERIFY_MODE: none, mails do get delivered, but I don’t think that it’s secure? (I get 10/10 on tho with this setting)

If someone can give me some feedback about this, I would really appreciate it.

The problem appears to be that’s certificate is bad. Perhaps has some other name that you should be using.

Could you be a bit more clear about this? My mailserver’s SSL certificate is issued by Let’s Encrypt, but that’s behind the 465 port (i use 26, 465 doesn’t work at all) and my Discourse is certified by CloudFlare. I am not sure if I’m getting the whole certificate thing.

This is the one that’s broken:

SMTP address:

either whoever manages that mail server has it misconfigured and/or it answers to but it has a certificate only for (something like) Whoever manages that server is who to ask. This is not a problem with Discourse. If you manage the mail server, either figure out how to fix the certificate, or just punt and use the DISCOURSE_SMTP_OPENSSL_VERIFY_MODE, which works.

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Alright, thank you very much, I will try to figure it out, also gonna contact the email server provider.
Thanks again!
Best regards

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