Questions about not being able to send emails to Yahoo,sina and other addresses

Source: Internet
Author: User
Tags rfc mx record nslookup nslookup command reverse dns
The problem is due to anti-spam software, which has been confirmed by Sina that they recently deployed a set of anti-spam systems. By default, the mail server sends its own FQDN name when it makes a helo command to establish a session with a Remote mail server through port 25. Some of the current anti-spam software may be reversed by the FQDN name sent out by the mail server, and the connection will be disconnected for backward resolution failures.

The reverse parsing failed for the following reasons:

In the domestic, many administrators do not strictly follow the requirements of the domain resolution to do, think that pass on the line. The recommended approach is: to the domain name abc.com to do these parsing (add or subtract according to need)
1, host a record abc.com
2, host a record mail.abc.com
3, host a record www.abc.com
4, host a record ftp.abc.com
5, abc.com to mail.abc.com MX record
6. Reverse Parse Record
Many people in the mail server will forget to do MX records and reverse parsing records, abc.com and mail.abc.com is not the same host, forget the MX record will be a lot of such problems, and then in the process of troubleshooting to add it. But is willing to do the reverse analysis of the administrator is very few, in foreign countries, many Unix master opportunity to check the domain name that you use when sending the mail, if the reverse parse impassability, your mail will be "clicks".
Then we do these parsing is not to send e-mail to Sina, NetEase, Sohu, 163.net and 263 will be no problem. Of course not....
Sina, for example, Sina's mail is two sets of systems: Charge and free, the MX address of the two sets of systems is also different. The free suffix is @sina.com and the charge is for @vip.sina.com. In addition to the limit on mailbox capacity, the free mail system there will also be a limit on the number of messages: that is, within a period of time, if the number of messages from the same IP to Sina free mailbox more than a certain number of restrictions, the IP address will be blocked by the free mail system, blocked time will not be able to send mail to Sina free mail system.
After about 15-20 minutes, the IP address will automatically be removed from the IP address list if the IP address does not send a message to it. Another: This issue was summed up in early August, now Sina's billing system has no such rules did not ask Sina.
If your IP in the stipulated time has not lifted the blockade, then cries to Sina's administrator to call it, said to him: eldest brother, I beg you, you when I am a fart, put me to release ...
This rule is not only Sina, Sohu, 163, 263 and so on. This is a good way to prevent spam, but it also causes the mailing list to not be sent properly. This is why you can't get a mailing list of many service providers with the above mailbox.
This rule is the Administrator on the server to do the settings, the average user temporarily do not think. Use the IMAIL administrator to get your boss to spend money on declude plug-ins to achieve this.


Try the following debugging methods:
1. Ping the name of the FQDN of the mail server and confirm that you can resolve the
The IP address that should be applied.
If not, is there a mail server on the Internet DNS server
A record

2. Query through the nslookup for all the ability to send outgoing mail directly
The mail server added an MX record



A. Mail sent to Sina.com will be returned

The email I sent to Sina will be returned and prompted "remote server said:553 Spam mail http://mail.sina.com.cn/FAQ.html";

Access Http://mail.sina.com.cn/FAQ.html We can learn that Sina has helo domain validation. Please note that setting up the HELO domain in the mail system, if you can not send to Sina's mailbox after following these actions, there are several possibilities:
1 MX point may be incorrect, please carefully check the MX point is correct
2 Your server IP address may be blocked by Sina, you need to contact Sina Customer service, SINA customer service Contact email: antispam@staff.sina.com.cn Sina Customer Service Tel: 010-82624488-5602, contact with each other, Please provide your server information: Host ip/domain name/letter of return/Send address/receiving address/sending time, in order to solve your problem in time. At the same time, be sure to leave each other's work number, so as to facilitate the resolution of problems.

Http://mail.sina.com.cn/FAQ.html #q3
1. Why Sina server will generate 553 of the message of withdrawal?
This is due to the HELO domain setting of the Mail sender server. If the Sina server is unable to do the correct DNS resolution of this domain, it will cause the Sina anti-spam system to think that the server is a spam sender and reject it. An example of a nonstandard helo domain is as follows:

HELO Office
HELO mailserver
HELO Localhost.localdomain

Workaround: Refer to the Setup method provided in the second half of this document to correctly set up the HELO domain of your SMTP server so that Sina can make the correct DNS resolution of the domain name

2.SMTP server can be set up for the company intranet domain name.
Please set your company's server to send the HELO domain as the correct domain name for your company, otherwise it will be due to the same reasons as the first Sina rejected.


The helo domain for the 3.SMTP server is set up correctly, and how to generate 553 of the message back.
This is because the outgoing mail server is in a network segment of the network. If the message is sent through a firewall, and the firewall does not map the source IP address of the message, Sina's server will assume that the IP of the firewall is the IP address of the sender's SMTP server, and that the message source IP address is inconsistent with the HELO domain name MX resolution. This will also make Sina reject mail. Workaround: Make the domain name MX after helo resolution to the IP address of the firewall, or enable the firewall to map the IP of its message to its true IP address, that is, do not change the source IP address of the message.


The helo domain of the 4.SMTP server can contain special characters.
No. If the helo domain of the outgoing mail server contains unrecognized characters, it will cause Sina to fail its DNS resolution and thus refuse to receive its messages.
Example of an helo domain containing unrecognized characters: Eev?bj?md02.vatech


5. How to set up the SMTP server correctly for foreign websites.
Sina requires all CMTP servers outside the mainland to provide reverse DNS resolution. For CMTP servers outside China, if no reverse DNS resolution is provided, Sina will consider the server to be the spam sender's server and reject mail from the address.
WORKAROUND: Register the RDNS service of the Internet IP address of the SMTP server, and write the corresponding domain name to the server's helo domain.


6.MS Exchange Server server helo domain settings method
Specific location in:
A.exchange 2000:server---Host name---SMTP---DEFAULT SMTP VIRTUAL---properties---DELIVERY---ADVANCED---masquerade name
B.exchange 2003: Server-Host name-protocol-SMTP---Default virtual SMTP Server---Properties-delivery-advanced-Fully restricted domain name, as shown below:

The setting method of 7.Notes server helo domain
Location: Server---Basic---fully qualified Internet host name

The 8.imail helo should be Host Name on the general panel of localhost
such as host name here is hi.com so imail use is Helo hi.com
In addition IMAIL management panel-"service-" smtp-"Advance->hello message->hii.com only modify is the banner information of SMTP

The HELO of 9.MDaemon server is set in setup-Primary domain-HELO Domain name.

10Winmail Server settings: Administrative Tools-> system settings->SMTP set-> basic parameters->helo/ehlo host name. Available nslookup command lookup, yourdomain MX preference = ten, mail exchanger = The following is the correct HELO/EHLO host name.



If you meet the above requirements, send to Sina or be returned the same letter, please contact Sina. Contact method is as follows:
e-mail address: or
Contact Tel: 010-82624488 ext. 5602
You can also apply for a Sina mailbox, mail system after the delivery failed to enable relay delivery, Relay server: smtp.sina.com.cn, and then enter your registered user name and password in Sina.

------------------------------------------------------------------------------------------------
A few days ago, Sina Mail according to international standards, the Sina Mail anti-spam strategy to adjust.
During this period, such as the occurrence of a letter to Sina abnormal or received from Sina's withdrawal tips, please refer to the log or error code, in accordance with the RFC standards to adjust your letter mechanism, thank you for your cooperation.

First of all, please check the helo information of the sending server is the full domain name, if not will be the system defaults to spam, related setup issues can refer to system return information and server basic

Set of help documents: http://antispam.sina.com.cn/

Second, in the sending server to do Telnet test, the results of the Telnet to save and send to the mailbox, also attached to the sender's server IP address,

The domain name, the unit name, the contact telephone, the contact person and so on information, in order to carry on the specific technical consultation.

The Telnet test format is as follows:

Telnet sinamx.sina.com.cn 25
SINAMAIL.SINA.COM,CN ESMTP Postfix <postfix rulse!>
Helo xx.com (your correct helo information)
sinamail.sina.com.cn
Mail from:<> (your enterprise mailbox name)
Ok
RCPT to:<> (your test email must be for Sina Mail)
Ok
RCPT to:<> (our test email)
Ok
Data
354 Please continue-go ahead
From:
To:
Subject:abc
Date:thu, Mar 2004 14:50:55 +0800
mime-version:1.0
Content-type:multipart/alternative
This is a test letter from Telnet.
.(“.” Not to be ignored)
Quit


If you can see a sina.com ESMTP this statement, you can determine that you are not rejected as spam, and the query is not in the blacklist.
Please note: If you are using a Windows Server, be careful not to use Delete, back, and so on in the above operation. If you enter an error, exit and repeat the Telnet test as required.

Annex I: Meaning of error codes and solutions

First, the sender mail server must be in strict accordance with the RFC821 (simple Mail Transfer Protocol) International standard, while complying with RFC1035 (Domain names-implementation and Specification) the designation of the domain name by international standards.
Second, because does not conform to the current Sina's anti-spam strategy is rejected, obtains the error code for the following several, requests the complainant according to the log or the error code to make the modification.
If the complainant is an ordinary user, please complain to his mail service provider to provide relevant information, by his administrator to modify the operation.

3.1 Error code: 450 4.7.1 Client host Rejected:cannot Find your hostname
Error reason: The opposing server does not set a reverse resolution
Processing method: Please refer to http://www.5dmail.net/html/2006-1-20/2006120225656.htm

3.2 Error code: 450 4.7.1 Helo command rejected:host not found
Error reason: The domain name provided by the opposing server in the HELO command cannot be resolved
Processing method: Please check the domain name information provided by its HELO command, and ensure that it complies with the RFC1035 International standard.

3.3 Error code: 504 5.5.2 Helo command rejected:need fully-qualified hostname
Error Reason: Helo information for the opposing server is not a full domain name
Processing method: Ask the other party to check the domain name information provided by its helo order and ensure that it complies with the RFC1035 International standard.

3.4 Error Code: 501 5.5.2 Helo Command rejected:invalid name
Error reason: The helo information for the opposing server contains illegal characters
Processing mode: RFC stipulates that the information provided by the HELO command must not contain Chinese characters.
Please the other party in accordance with RFC1035 international standards, its helo information settings to modify.

3.5 Error code: 554 5.7.1 Recipient address Rejected:dynamic IP
Error reason: The opposite server uses dynamic IP processing: Please see the People's Republic of China Ministry of Information Industry of the 38th "Internet e-mail Service management measures" in the fourth: Article fourth provides Internet e-mail services, The operation license of value-added telecommunication business should be obtained beforehand or the record formalities of non operating Internet Information service should be fulfilled according to law. No organization or individual may carry out Internet e-mail services in the territory of the People's Republic of China without obtaining the business license for value-added telecommunications business or failing to perform the filing procedures for non-operating Internet Information services.

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