Hello friends
I am an email administrator at university and I use Exchange 2016. it is 2 years that I use Efa for spam filtering but I have important problem with EFA.
Emails from some domains don't receive to us. with this error: 450.4.7.1 cannot find reverse hostname. I checked those senders, some of them have reverse DNS(but they were in blacklist(not our blacklist)) and some of them don't have reverse DNS. Why those senders can send to other mail servers easily but we can not receive their emails by EFA, Also our reverse DNS is correct. what can I do? I put the sender address in whitelist but i was not succeed. Could you please help me?
I need your guidance.
thanks, beforehand
client host rejected error
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shawniverson
- Posts: 3649
- Joined: 13 Jan 2014 23:30
- Location: Indianapolis, Indiana USA
- Contact:
Re: client host rejected error
If a sender doesn't have a proper PTR record for their domain, postfix will reject them. The proper solution is to notify the sender domain and tell them to fix their PTR record.
You can make exceptions to the this using a postfix sender access list.
On eFa, this list is here:
/etc/postfix/sender_access
For more information:
http://www.postfix.org/postconf.5.html# ... strictions
You can make exceptions to the this using a postfix sender access list.
On eFa, this list is here:
/etc/postfix/sender_access
For more information:
http://www.postfix.org/postconf.5.html# ... strictions