Topic: E-mail Filtering Using Black and White Lists

Black and White lists are lists of wanted (White) or unwanted (Black) e-mail peers. Lists can be by Domain, IP address, e-mail address and can include partial information (part of a domain, IP address or e-mail address)

Use White lists to ensure wanted e-mail (possibly from sources that PerfectMail would otherwise tag or reject as Spam) is always delivered to your users.

Use Black lists to prevent unwanted e-mail sources that are not blocked by PerfectMail from sending spam to your recipients (where PerfectMail would otherwise incorrectly fail to filter the e-mail as unwanted).

Navigation: Filters => Black / White List

Screen shot showing PerfectMail's White List, Black List and No Server Checks settings...

Brief Description

To White List an e-mail peer, add their e-mail address, domain or IP address to the White List form and click Update. To permanently block e-mail from a peer, add their e-mail address, domain or IP address to the Black List form and click Update. To prevent PerfectMail from doing peer mail server validation checks (domain name correct, DNS entry correct, reputation OK, etc.), add a peer mail server to the No Server Checks list (particularly effective for legitimate mail servers that are not configured to e-mail server best practices) and click Update.

Note: Black Lists and White Lists are site wide so everyone's e-mail is impacted by your settings. At this time, PerfectMail does not support individual user or domain Black / White lists.

Full Description

(Taken from PerfectMail's help article on Black / White List page)

The following tables adjust filtering for mailhosts, domains and e-mail addresses. Using these tables it is possible to block content for whole countries.

List known good servers on the white-list to ensure e-mail from important servers does not get blocked. Often infrastructure servers (production servers, web servers, etc.) send e-mail notifications; but these servers often tend to be poorly configured as mail servers. Add these servers to the white list so their messages do not get blocked.

Table Format:
Each table accepts entries using the following formats. Certain format types may not make sense for all tables; please refer to the appropriate table description below for more information. The following formats are supported:

• IP Address: X.X.X.X or X.X.X.X/Y - to specify an IP address or net block. For example:

  192.168.1.3
  192.168.2.0/24
  
  

• Host Name: Specify the Fully Qualified Domain Name (FQDN) of a specific host. For example:

  myhost.domain.com
  yourhost.yourdomain.com
  
  

• Domain: Specify a complete domain, including sub domains. Each portion of the domain name must be specified fully; wild cards are not supported. For example:

  newyork.customer.com
  company.com
  
  

• E-mail Address: Specify complete e-mail addresses. This is particularly useful for domains that commonly send spam. For example:

  user@domain.com
  
  

• User: Specify the user portion of an e-mail address. This is useful for specifying commonly used e-mail addresses, across multiple domains. For example:

  sales@
  webmaster@
  
  

White List

White listed senders will be accepted regardless of content. White listing takes precedence over all other checks, except for virus scans. You can list IP addresses, hostnames, domains and e-mail addresses.

No Server Checks

Sometimes there are problems with the configuration of the sending server that you don't have any control over. For various reasons, the sender may not be able to fix their issues in a timely manner. Usually this happens when servers get listed on RBL (Real-time Block List) services due to server configuration issues or have problems with their SPF (Sender Policy Framework) configurations.

Domains and mail servers listed here will not be checked against RBL lists, SPF validation or any other server reputation checks PerfectMail™ may perform. You can list IP addresses, hostnames and domains.

Black List

Black listed senders will be rejected, regardless of content. When domains or combination of sub-domains are entered on multiple lists, the most permissive list takes precedence, (E.g. white-listing takes precedence over black-listing). You can list IP addresses, hostnames, domains and e-mail addresses.

Special Notes for News Groups

News Group services such as Yahoo Groups react negatively to anti-spam software. For example, if messages forwarded from Yahoo Groups are rejected, Yahoo Groups will stop forwarding messages to the protected e-mail address. For situations like this create white-list entries for such services and rely on their anti-spam services.