==== REQUIRED BASIC INFO OF YOUR IREDMAIL SERVER ====
- iRedMail version (check /etc/iredmail-release): 0.9.8
- Deployed with iRedMail Easy or the downloadable installer? Download
- Linux/BSD distribution name and version: CentOS 7.6.1810
- Store mail accounts in which backend (LDAP/MySQL/PGSQL): PGSQL
- Web server (Apache or Nginx): Nginx
- Manage mail accounts with iRedAdmin-Pro? NO
- [IMPORTANT] Related original log or error message is required if you're experiencing an issue.
====

Hello,

Several users receiving the "451 4.3.0 Temporary lookup failure" multiple times this AM. Logs are showing a lot of these entries:

Oct 30 10:47:50 puffin postfix/trivial-rewrite[26674]: warning: proxy:pgsql:/etc/postfix/pgsql/transport_maps_user.cf lookup error for "thisuser@ourdomain.com"
Oct 30 10:47:50 puffin postfix/trivial-rewrite[26674]: warning: transport_maps lookup failure

How do I trouble shoot this? Is this a Postfix or a Postgresql issue?

Thanks much!