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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[8790]: NOQUEUE: reject: RCPT from melgw2.ultradata.com.au[210.193.160.202]: 450 4.7.1 <proxymel.ultradata.com.au>: Helo command rejected: Host not found; from=<xxxxxxx@ultradata.com.au> to=<xxxxxx@sydneywebcreations.com.au> proto=SMTP helo=<proxymel.ultradata.com.au>
May  2 11:42:29 mail postfix/smtpd[8790]: disconnect from melgw2.ultradata.com.au[210.193.160.202] helo=1 mail=1 rcpt=0/1 quit=1 commands=3/4
root@mail:~#


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.

Thanks
Jim

----

Spider Email Archiver: On-Premises, lightweight email archiving software developed by iRedMail team. Supports Amazon S3 compatible storage and custom branding.

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Re: Helo command rejected: Host not found; Whitelist not working

The whitelist/blacklists managed in iRedAdmin-Pro are based on sender email address and IP address, not HELO identity.
In your case, please fix it this way:

*) Find parameter "smtpd_helo_restrictions" in /etc/postfix/main.cf like below:

smtpd_helo_restrictions =
    permit_mynetworks
    permit_sasl_authenticated
    reject_non_fqdn_helo_hostname
    reject_unknown_helo_hostname
    check_helo_access pcre:/etc/postfix/helo_access.pcre

*) Move "    check_helo_access pcre:/etc/postfix/helo_access.pcre" like below:

smtpd_helo_restrictions =
    permit_mynetworks
    permit_sasl_authenticated
    check_helo_access pcre:/etc/postfix/helo_access.pcre
    reject_non_fqdn_helo_hostname
    reject_unknown_helo_hostname

Reloading or restarting postfix srevice is required.
*) Add a whitelist (in top of file) in file /etc/postfix/helo_access.pcre. like this:

/^proxymel\.ultradata\.com\.au$/ DUNNO

3

Re: Helo command rejected: Host not found; Whitelist not working

May  3 14:03:14 mail postfix/smtpd[22494]: connect from melgw2.ultradata.com.au[210.193.160.202]
May  3 14:03:14 mail postfix/smtpd[22494]: NOQUEUE: reject: RCPT from melgw2.ultradata.com.au[210.193.160.202]: 450 4.7.1 <proxymel.ultradata.com.au>: Helo command rejected: Host not found; from=<> to=<enquiries@camdenchamber.com.au> proto=SMTP helo=<proxymel.ultradata.com.au>
May  3 14:03:14 mail postfix/smtpd[22494]: disconnect from melgw2.ultradata.com.au[210.193.160.202] helo=1 mail=1 rcpt=0/1 quit=1 commands=3/4

I followed the instructions and restarted postfix  I added /^proxymel\.ultradata\.com\.au$/ DUNNO into  helo_access.pcre

As you can see above it is still rejecting

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Re: Helo command rejected: Host not found; Whitelist not working

jwmcgregor wrote:

I added /^proxymel\.ultradata\.com\.au$/ DUNNO into  helo_access.pcre

Please replace DUNNO by OK and try again.

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Re: Helo command rejected: Host not found; Whitelist not working

To add to this had trouble receiving emails from the US Treasury and ATT among others. For this reason commented out:
#reject_unknown_helo_hostname
in /etc/postfix/main.cf

Apparently lots of "big organizations" have unresolvable domains in their helo hostname.

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Re: Helo command rejected: Host not found; Whitelist not working

@schnappi i had the same Problem, i couldn't also receive some mails (i.e. my bank). Your solution did the trick, now i can receive mails, thx.