Question: 04 TLS server with iRedMail installed. When just installed it worked okay but after 4 emails I get a error message

> 
> Sep 9 12:24:18 hostname postfix/smtp[9907]: connect to 127.0.0.1[127.0.0.1]:10024: Connection refused
>  Sep 9 12:24:18 hostname postfix/smtp[9907]: D97C720A31: to=, relay=none, delay=1.1, delays=1.1/0.02/0/0, dsn=4.4.1, status=deferred (connect to 127.0.0.1[127.0.0.1]:10024: Connection refused)
>  Sep 9 12:24:19 hostname postfix/smtpd[9892]: disconnect from localhost[127.0.0.1]
> 
> 
> 

I don't know where the problem is. Can someone help me out here?

Answer: 
I ran into something similar recently. In my case, scanning the logs I noticed some memory allocation errors and this, together with some hints from pages, suggested to me that the node didn't have enough RAM to operate properly. I've subsequently added 1GB of swap which seems to have helped. So I'd tentatively suggest it's a low memory condition -- add some RAM and reboot and see if things improve, and look through your logs for errors.
Run postmap command on conf files in /etc/postfix/ and restart postfix service.