======== 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.
====

Feb 19 18:10:05 rmail postfix/smtpd[13357]: NOQUEUE: reject: RCPT from _gateway_: 451 4.3.0 <Marina.Portnova@myexternaldomain>: Temporary lookup failure; from=<Marina.Portnova@myexternaldomain> to=<kaluga@mydomain> proto=ESMTP helo=<major-express.ru>
Feb 19 18:10:13 rmail postfix/trivial-rewrite[18346]: warning: proxy:mysql:/etc/postfix/mysql/transport_maps_user.cf lookup error for "еzra@shouldexist.org"
Feb 19 18:10:13 rmail postfix/trivial-rewrite[18346]: warning: transport_maps lookup failure
Feb 19 18:10:13 rmail postfix/trivial-rewrite[18346]: warning: proxy:mysql:/etc/postfix/mysql/transport_maps_user.cf lookup error for "tomsk@mydomain"
Feb 19 18:10:13 rmail postfix/trivial-rewrite[18346]: warning: transport_maps lookup failure
Feb 19 18:10:13 rmail postfix/smtpd[18124]: NOQUEUE: reject: RCPT from _gateway_: 451 4.3.0 <еzra@shouldexist.org>: Temporary lookup failure; from=<еzra@shouldexist.org> to=<tomsk@ mydomain > proto=ESMTP helo=<shouldexist.org>
Feb 19 18:10:17 rmail postfix/trivial-rewrite[18346]: warning: proxy:mysql:/etc/postfix/mysql/transport_maps_user.cf lookup error for "donald@somany.org"
Feb 19 18:10:17 rmail postfix/trivial-rewrite[18346]: warning: transport_maps lookup failure
Feb 19 18:10:17 rmail postfix/trivial-rewrite[18346]: warning: proxy:mysql:/etc/postfix/mysql/transport_maps_user.cf lookup error for "tomsk@ mydomain "
Feb 19 18:10:17 rmail postfix/trivial-rewrite[18346]: warning: transport_maps lookup failure
Feb 19 18:10:17 rmail postfix/smtpd[27467]: NOQUEUE: reject: RCPT from _gateway_: 451 4.3.0 <donald@somany.org>: Temporary lookup failure; from=<donald@somany.org> to=<tomsk@ mydomain > proto=ESMTP helo=<somany.org>
Feb 19 18:22:06 rmail postfix/trivial-rewrite[1829]: warning: proxy:mysql:/etc/postfix/mysql/transport_maps_user.cf lookup error for "еzra@goetiamagick.org"
Feb 19 18:22:06 rmail postfix/trivial-rewrite[1829]: warning: transport_maps lookup failure
Feb 19 18:22:06 rmail postfix/trivial-rewrite[1829]: warning: proxy:mysql:/etc/postfix/mysql/transport_maps_user.cf lookup error for "omsk@ mydomain "
Feb 19 18:22:06 rmail postfix/trivial-rewrite[1829]: warning: transport_maps lookup failure
Feb 19 18:22:06 rmail postfix/smtpd[1827]: NOQUEUE: reject: RCPT from _gateway_: 451 4.3.0 <еzra@goetiamagick.org>: Temporary lookup failure; from=<еzra@goetiamagick.org> to=<omsk@ mydomain > proto=ESMTP helo=<goetiamagick.org>
Feb 19 18:31:38 rmail postfix/smtpd[1827]: NOQUEUE: reject: RCPT from _gateway_: 451 4.3.0 <omsk@ mydomain >: Temporary lookup failure; from=<isaac@getsocialmedia.org> to=<omsk@ mydomain > proto=ESMTP helo=<getsocialmedia.org>

also i get

Feb 19 18:43:19 rmail postfix/proxymap[2578]: warning: mysql query failed: Illegal mix of collations (latin1_swedish_ci,IMPLICIT) and (utf8_general_ci,COERCIBLE) for operation '='

===

Hello,

All of a sudden users started to claim for error 4.3.0 temporary lookup failure when sending emails. Also I think they not recieving some emails. I've tried to search via forum and internet, but it only confused me.
For the illegal mix of collations - my sql was set up to use UTF8 and all bases are using UTF8, i dont remember if I saw that error when done configuring.
Server was updated in october from 0.9.5 to 0.9.6, but worked fine up to last week with no issues.
Will appreciate any help on finding a direction to fix.

Best regards,
Anton.