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Campanha Anti SPAM

This page provides information to information technology professionals who administer systems that send and receive email to/from some server powered by Specialist Linux Solutions (many tips and rules contained herein apply to other providers and hostings “politicament correct” as well, such as Hotmail , Yahoo, Terra and many others). However, it is not intended to provide extensive support to end users. If you are a end-user and need support, please visit the page Suporte or contact your technical support if you are not a customer of Specialist.

-> See the Specialist blacklist
-> If you are having routing problems, see page “NOC
-> To have knowledge of the Anti-SPAM’s Specialist, see the page “Sobre o Anti-SPAM
-> To be aware of our Anti-SPAM policy, see the page “Política Anti-SPAM

1) verify that the IP of your mail server, have Reverse DNS configured, and the names of reverse signals back to the server’s IP. Often such errors, which implies serious problems for the delivery of messages on many providers. A good test to validate its reverse is to use the tool of the Terra in

2) Check if your IP is not listed in blacklist in (a tool from MX Toolbox that queries dozens of blacklists in the world).

3) For the delivery of messages on servers powered by Specialist, we also have a own blacklist. See it!

4) Check if your domain has SPF registered in DNS, if not own, it is a good set it up (see more at and if you already have, see if you yourself are not in contravention of the rules of the (many have the DNS and the site hosted on an ISP X, which sets the standard for SPF on your domain, so that only the servers of the provider can send mail with it, however it is using a mail server itself , typically located within the company, but the administrator forgets or does not know you need to update the SPF DNS entry by putting the IP of this server).

5) Make sure you are using the latest version of all software used on the mail server, reducing the chances of it being a bug affecting the delivery.

6) See if the relay is closed (this is extremely important). Only users of the server must send out emails using the server for the relay, this control can be done by IP, SMTP authentication (the most common and feasible) or by pop-before-smtp. If your server is open to relay, it is likely that the same IP is listed on several blacklists, causing problems for mail delivery by service providers / hostings with minimal antispam installed.

7) there are several other things I can still quote in particular put the most important (or the ones I remembered). Over the days I’ll fill this page better, trying to help someone who may be having problems. In particular, view and review the links below to make sure everything is in order with your IP / Server.

Abstract / Some useful links:

– Check Reverse DNS and other items required for message delivery in the vast majority of providers and Hostings:
– Complete check your DNS table: and
– Check whether it is possible to reach your DNS servers and DNS performed Route:
– Check whether your mail server is running Open Relay:
– Check if your IP is listed in any blacklist: (especially see the listings of Spamcop and both from Spamhaus, XBL and SBL) as well as check out the list from Specialist as reported above.
– Create the SPF entry on your DNS correctly, every day that passes, the tendency to stop unsolicited coming from domains without SPF some increases considerably.
– Learn about the use of DomainKeys, Sender ID and other ways that ensure the legitimacy of their emails.

Some pages of help from other providers / hostings:

MSN / Hotmail:
Microsoft (hotmail): (self-monitoring)
Blacklist of Specialist:

If you still have questions, contact
by email in Security Team Specialist