iredmail does not send mail Accepted

- iRedMail version:   iRedMail-0.8.7
- Store mail accounts in which backend (LDAP):
- Linux/BSD distribution name and version: debian 7
- Related log if you're reporting an issue:

hi
in the administration, I do not understand, but
I installed iredmail on vps (Debian 7) it could only send mails, after I created the mx record and create subdomain specifically for iredmail, he stopped sending mails
Now he does not send or receive emails
please help me