NOC | Postmaster

Network Operation Center & Postmaster Specialist

This page contains information for Network Administrators and E-mail Server Administrators who have problems with Specialist (and their customers), but if you are a Specialist customer, access the “Suporte Técnico” menu.

When is an IP blacklisted?
If we detect spams from an IP, we will notify Abuse of it (obtained by WHOIS) and in case of recurrence or when we get no response from Abuse, IP/Range will be put in our blacklist.

When is a domain is blacklisted?
By default, we avoid blacklisting a domain (or a specific sender), but there are special cases where we have no choice but to do so. Some spammers use dynamic IP connections or a “zombie machine” for SPAMMING (using a different server each time). In this case, we will blacklist the spammer’s domain.

My IP or domain is blacklisted, how to remove it from the list?
Please e-mail [email protected] (this is the only way to contact us) explaining what happened to your IP or domain, and explain what actions were taken to resolve the incident. Please do not send e-mails “requiring immediate release”, be polite and follow the procedures outlined here.


– Verify that the IP of your mail server, have reverse DNS configured, and the names of reverse get back to the server’s IP. A good test to validate its reverse is to use the tool of the Terra in
– Check if your IP is not listed in blacklist in (a tool from MX Toolbox that queries dozens of blacklists in the world)
– Create the SPF entry on your DNS correctly;
– Learn about the use of DomainKeys, Sender ID, SPF, SRS, DMARC and other ways that ensure the legitimacy of their emails;
– Read other tips in, and especially and (both for you to monitor yourself)

About our Network:

If you are having trouble accessing our servers in our Data Center, check how are the routes to access them.

Use an LG (Looking Glass) and see how your routes are to us. We have a public LG at

Our IP Pools are, and 2804:1a4:1::0/112. We use ASN 28140, which belongs to Maxiweb, owner of the Data Center where we are. We use several links for Transit IP and we are in the largest internet exchange in Brazil, IX-SP.

We do not block ping based in ICMP packets (but we do block based in UDP packets).

If you still have questions or need to contact us regarding a problem, please contact us at [email protected] or call INOC-DBA at 28140*100