# Troubleshooting Email Errors Email communication is crucial for any organization, but issues can arise that disrupt this essential service. This guide provides practical steps to diagnose and resolve common email errors encountered in [OpenPanel Enterprise edition](/product/openpanel-premium-control-panel/), ensuring your email systems run smoothly and efficiently. ## ERROR list mail user: '/tmp/docker-mailserver/postfix-accounts.cf' does not exist Dovecot is not started until the first email account is created, therefor listing email accounts with the command `opencli email-setup email list` before creating any email accounts, will produce error: ```bash root@stefi:/usr/local/mail/openmail# opencli email-setup email list 2024-08-27 07:55:15+00:00 ERROR listmailuser: '/tmp/docker-mailserver/postfix-accounts.cf' does not exist 2024-08-27 07:55:15+00:00 ERROR listmailuser: Aborting ``` **Solution**: Create an email account first with [opencli email-setup email add](https://dev.openpanel.com/cli/email.html#Create-email). ---- ## Error: auth-master: userdb lookup(user@example.net): connect(/run/dovecot/auth-userdb) failed: No such file or directory Immediately after creating first email account, dovecot is still creating necessary files in the background, so running the `opencli email-setup email list` immediately after creating first email account will produce an error: ``` root@stefi:/usr/local/mail/openmail# opencli email-setup email list doveadm(stefan@stefi.openpanel.site)<577><>: Error: auth-master: userdb lookup(stefan@stefi.openpanel.site): connect(/run/dovecot/auth-userdb) failed: No such file or directory doveadm(stefan@stefi.openpanel.site): Error: User lookup failed: Internal error occurred. Refer to server log for more information. 2024-08-27 07:55:46+00:00 ERROR listmailuser: Supplied non-number argument '' to '_bytes_to_human_readable_size()' 2024-08-27 07:55:46+00:00 ERROR listmailuser: Aborting 2024-08-27 07:55:46+00:00 ERROR listmailuser: Supplied non-number argument '' to '_bytes_to_human_readable_size()' 2024-08-27 07:55:46+00:00 ERROR listmailuser: Aborting * stefan@stefi.openpanel.site ( / ) [%] ``` **Solution**: Repeat the command `opencli email-setup email list` ----