AOL doesn't receive E-mail from Zimbra users

[bill77se]

Hi,

First of all I want to thank you guys for a great job. Is wonderful this Zimbra the best E-mail we can get.

I've installed Zimbra 7.13 on Ubuntu 64 Bits, everything is working very well. But when users are sending mail to AOL they remain in queue in the server.
The messages are:

************************************************** ********
Dec 6 07:27:23 domain1 postfix/smtp[26594]: 3C51FC2F4F: host mailin-03.mx.aol.com[205.188.156.193] refused to talk to me: 421 4.7.1 : (DNS:NR) AOL Postmaster | Postmaster / AOL SMTP Error Messages
Dec 6 07:27:25 domain1 postfix/smtp[26594]: 3C51FC2F4F: host mailin-04.mx.aol.com[205.188.103.2] refused to talk to me: 421 4.7.1 : (DNS:NR) AOL Postmaster | Postmaster / AOL SMTP Error Messages
Dec 6 07:27:29 domain1 postfix/smtp[26594]: 3C51FC2F4F: host mailin-04.mx.aol.com[64.12.90.34] refused to talk to me: 421 4.7.1 : (DNS:NR) AOL Postmaster | Postmaster / AOL SMTP Error Messages
Dec 6 07:27:34 domain1 postfix/smtp[26594]: 3C51FC2F4F: host mailin-04.mx.aol.com[64.12.138.161] refused to talk to me: 421 4.7.1 : (DNS:NR) AOL Postmaster | Postmaster / AOL SMTP Error Messages
Dec 6 07:27:36 domain1 postfix/smtp[26594]: 3C51FC2F4F: to=<........@aol.com>, relay=mailin-02.mx.aol.com[205.188.103.1]:25, delay=35962, delays=35944/0.04/18/0, dsn=4.7.1, status=deferred (host mailin-02.mx.aol.com[205.188.103.1] refused to talk to me: 421 4.7.1 : (DNS:NR) AOL Postmaster | Postmaster / AOL SMTP Error Messages)
Dec 6 07:27:36 domain1 postfix/smtp[26594]: 3C51FC2F4F: to=<562@aol.com>, relay=mailin-02.mx.aol.com[205.188.103.1]:25, delay=35962, delays=35944/0.04/18/0, dsn=4.7.1, status=deferred (host mailin-02.mx.aol.com[205.188.103.1] refused to talk to me: 421 4.7.1 : (DNS:NR) AOL Postmaster | Postmaster / AOL SMTP Error Messages)
************************************************** ********
The others E-mail server as gmail yahoo etc. doesn't have any problem to receive the e-mails.

Best Regards

[phoenix]

No. the loopback adapter should not be removed from the Trusted Network settings.

The answer to your problem seems fairly clear to me. You've been pointed (by the received error message) to a help page that states the following:

421 DNS:NR

The Reverse DNS lookup for your IP address is failing. This could be a transient issue. Confirm the IP that sends your mail. Then check the rDNS of that IP using our troubleshooting tools. If it passes, please wait 24 hours and re-try before opening a support request.
rDNS must be in the form of a fully-qualified domain name. rDNS containing in-addr.arpa are not acceptable, as these are merely placeholders for a valid PTR record. rDNS consisting of IP addresses are also not acceptable, as they do not correctly establish the relationship between domain and IP address.
rDNS that may be similar to dynamic IP space (containing pool, dhcp, dyn, etc.) may be treated as suspect, and should therefore should be changed to reflect a fully-qualified domain name with standard reverse DNS.

Fix that error and your problem will go away.