An error is reported when the Postfix in iredmail is sent: [need fully-qualified hostname]

After iredmail is configured, try to send an email from the client's Oe. An error is returned. Check tail/var/log/maillog on the mail host and find the following error message:

Oct 24 12:50:49 mail2 postfix/smtpd[9280]: connect from unknown[192.168.5.240]Oct 24 12:50:49 mail2 postfix/smtpd[9280]: NOQUEUE: reject: RCPT from unknown[192.168.5.240]: 504 5.5.2 <dzDevelop>: Helo command rejected: need fully-qualified hostname; from=<[email protected]> to=<[email protected]> proto=ESMTP helo=<dzDevelop>Oct 24 12:50:49 mail2 postfix/smtpd[9280]: NOQUEUE: reject: RCPT from unknown[192.168.5.240]: 504 5.5.2 <dzDevelop>: Helo command rejected: need fully-qualified hostname; from=<[email protected]> to=<[email protected]> proto=ESMTP helo=<dzDevelop>Oct 24 12:50:49 mail2 postfix/smtpd[9280]: disconnect from unknown[192.168.5.240]Oct 24 12:52:11 mail2 postfix/smtpd[9280]: connect from unknown[192.168.5.240]Oct 24 12:52:11 mail2 postfix/smtpd[9280]: NOQUEUE: reject: RCPT from unknown[192.168.5.240]: 504 5.5.2 <dzDevelop>: Helo command rejected: need fully-qualified hostname; from=<[email protected]> to=<[email protected]> proto=ESMTP helo=<dzDevelop>Oct 24 12:52:11 mail2 postfix/smtpd[9280]: NOQUEUE: reject: RCPT from unknown[192.168.5.240]: 504 5.5.2 <dzDevelop>: Helo command rejected: need fully-qualified hostname; from=<[email protected]> to=<[email protected]> proto=ESMTP helo=<dzDevelop>

After exploration, I found that I only need to modify the Postfix configuration file. My Postfix configuration file is located in/etc/Postfix/Main. Cf.

Open Vim/etc/Postfix/Main. CF in the editor, find the smtpd_helo_restrictions line, and save the modification as follows.

Response = response = yes # response = permit_mynetworks, response, check_helo_access PCRE:/etc/Postfix/helo_access.pcre # modify the following content in the previous line, remove response = permit_mynetworks, response, reject_invalid_helo_hostname, check_helo_access PCRE:/etc/Postfix/helo_access.pcre

Restart Postfix

Service Postfix restart

Send again, OK

An error is reported when the Postfix in iredmail is sent: [need fully-qualified hostname]