Cannot issue SSL for mail server

Like the title says, I am unable to issue SSLs for my mailserver, which obviously keeps me from logging into my mails in external applications like thunderbird or outlook. I am also unable to send any.

This is the error I recieve when trying to issue a certificate for the mailserver:

[01.05.2022_22-37-59] Trying to obtain SSL for: domain . com
[01.05.2022_22-38-01] Successfully obtained SSL for: domain . com
[01.05.2022_22-38-01] {‘email@domain.com’: (550, b’5.1.1 email@domain.com: Recipient address rejected: User unknown in virtual mailbox table’)}

Any suggestions?I tried fixing this the entire day without success.

have you tried issuing ssl for your mail domain such as mail.yourdomain.tld ?

I get this when I try to do that. The SSL works fine for the domain itself though but for the Emails it wont do it.

[01.06.2022_18-54-04] Failed to obtain SSL, issuing self-signed SSL for: mail.domain .com
[01.06.2022_18-54-04] {‘email@mail.domain.com’: (554, b’5.7.1 <email@mail.domain .com>: Relay access denied’)}
[01.06.2022_18-54-04] Websites matching query does not exist. [installSSLForDomain:72]
[01.06.2022_18-54-04] Self signed SSL issued for mail.domain .com

Make sure you have A record for mail subdomain and it points to your server ip without proxy. Then only letsencrypt will be able to issue ssl for your mail domain.