Need some help on this...
On the admin page, global settings, MTA tab, I originally checked all the following:
Hostname in greeting violates RFC
Client must greet with a ...
Sender address must ...
Client's IP Address...
Hostname in greeting...
One of my users is getting some of his emails bounced by Zimbra. These messages are not spam but I think they have to do with the security settings that I have chosen.
The message that the originator gets back is:
The e-mail system was unable to deliver the message, but did not
report a specific reason. Check the address and try again. If it still
fails, contact your system administrator.
command rejected: Host not found>
Am I correct in assuming the originator's system is very lax in security and they are not following industry standards? Is this just a situation where they have a lazy sys admin who doesn't really know what he/she is doing?
What setting, in the Zimbra admin/global settings/MTA page do I have to undo so that this email can get through? I don't want to undo everything.
Since using Zimbra and all the special checks from the MTA tab the amount of SPAM has been almost reduced to 0.
Thanks in advance.