==== Required information ====
- iRedMail version (check /etc/iredmail-release): 0.9.6 MYSQL edition
- Linux/BSD distribution name and version: Ubuntu 16.04
- Store mail accounts in which backend (LDAP/MySQL/PGSQL): MySQL
- Web server (Apache or Nginx): Apache
- Manage mail accounts with iRedAdmin-Pro? No
- [IMPORTANT] Related original log or error message is required if you're experiencing an issue.
====

Hello,

So in my late night tinkering sessions with some web services, I decided to try and fix a problem by installing sSMTP which uninstalled postfix from my system. While doing this, I didn't stop to read if anything would be uninstalled as a result... I've now reinstalled it and it looks like only the main.cf and aliases.db files were overwritten but now I can't seem to send or receive email.

I'm still able to login to roundcube and see my email as well as use thunderbird to fetch email but that's all I can do.

Any help is appreciated,
- That8BitMan

EDIT: When trying to send an email I get the following error:

SMTP Error (451): Failed to add recipient "<recipient>" (4.3.0 <<user>@<domain>>: Temporary lookup failure).

EDIT 2: Here's what I got after trying to send an email to the server:

Transcript of session follows.

Out: 220 server.djsata.com ESMTP Postfix
In:  EHLO mail-ua0-f171.google.com
Out: 250-server.djsata.com
Out: 250-PIPELINING
Out: 250-SIZE 104857600
Out: 250-ETRN
Out: 250-STARTTLS
Out: 250-ENHANCEDSTATUSCODES
Out: 250-8BITMIME
Out: 250-DSN
Out: 250 SMTPUTF8
In:  STARTTLS
Out: 220 2.0.0 Ready to start TLS
In:  EHLO mail-ua0-f171.google.com
Out: 250-server.djsata.com
Out: 250-PIPELINING
Out: 250-SIZE 104857600
Out: 250-ETRN
Out: 250-ENHANCEDSTATUSCODES
Out: 250-8BITMIME
Out: 250-DSN
Out: 250 SMTPUTF8
In:  MAIL FROM:<<user>@gmail.com> SIZE=3146
Out: 250 2.1.0 Ok
In:  RCPT TO:<<user>@<domain>>
Out: 250 2.1.5 Ok
In:  DATA
Out: 354 End data with <CR><LF>.<CR><LF>
Out: 451 4.3.0 Error: queue file write error
In:  QUIT
Out: 221 2.0.0 Bye