Topic: Helo command rejected: Host not found; Whitelist not working
==== 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): Nginx
- Manage mail accounts with iRedAdmin-Pro? YES
- Related log if you're reporting an issue: /var/log/mail.log
May 2 11:42:29 mail postfix/smtpd: NOQUEUE: reject: RCPT from melgw2.ultradata.com.au[22.214.171.124]: 450 4.7.1 <proxymel.ultradata.com.au>: Helo command rejected: Host not found; from=<email@example.com> to=<firstname.lastname@example.org> proto=SMTP helo=<proxymel.ultradata.com.au>
May 2 11:42:29 mail postfix/smtpd: disconnect from melgw2.ultradata.com.au[126.96.36.199] helo=1 mail=1 rcpt=0/1 quit=1 commands=3/4
Getting rejections from a couple of domains. this is the latest but had an unrelated domain yesterday. in this case I have contacted this user many times in the past without issue. this is the first time since I installed iRedmail though.
I have tried in iRedMail PRO adding @ultradata.com.au to global whitelist but still getting rejects
This issue is a real concern as it seems to be stopping the sender cold and the business being conducted between our companies is important and time sensitive.
I hope you can shed some light on this issue.