Hi @krisztian8614, I'm an AI assistant for ZITADEL. While a team member reviews this question, I'll see if I can find relevant sources for your question.
I wasn't able to find a direct answer, here are some relevant sources:
[Test SMTP Email Provider](<https://zitadel.com/docs/apis/resources/admin/admin-service-test-email-provider-smtp-by-id>) : Describes how to send a test email to verify SMTP provider configuration in ZITADEL, including required API calls and example requests.
[Custom SMTP Didn't Send any Email](<https://discord.com/channels/927474939156643850/1384817110974337055>) : Discusses troubleshooting steps for SMTP issues, such as checking container logs for EMAIL errors, verifying DNS and port reachability, and potential issues with cloud providers blocking SMTP ports.