Below are a number of useful tools to help IT professionals correctly configure their mailing systems to achieve maximum delivery rates.

SPF

Open SPF — helps domain owners identify all servers which are allowed to send email on behalf of that domain.

SPF Validator — retrieves SPF records for the specified domain name and determines if the record is valid.

 
Sender ID

Microsoft Validator — a four-step wizard to guide you through the process of creating a new SPF record for your DNS domain

Skylist Validator — check the format of any DomainKey, Sender ID or SPF record published by your domain and see the result of these authentication checks on any message you send to it.

Domain Keys

Symetrix — generate Domain Keys.

Yahoo — a great resource for understanding how Domain Keys work and FAQs.

Sourceforge — Domain Key implementor tools and library for email servers and clients.

Sourceforge Policy Check Validator — tool for administrators to test their domains and check if DNS entries are valid, and to determine what policies exist.

Sourceforge Selector Check Validator — tool for administrators to test selectors to determine if the DNS entry is valid. Selectors are located in the _domainkey subdomain.

DKIM

Port25 Support — easily create a public and private key pair to be used for DomainKeys and DKIM signing.

DNS

DNS Stuff — tools and expertise for DNS and network configuration and testing.

DNS Report — analyzes 56 tests to identify and resolve DNS problems.

 
Open Relay Check

Abuse.net — email relay testing service.

HTML Validator

W3 — checks Web documents in formats like HTML and XHTML for compliance with industry standards.

Unsubscribe Button

List-Unsubscribe — header insert to enable the Unsubscribe button in Windows Live Beta (the next version of Hotmail) and for more than a million Cloudmark toolbar users.

Information About Senders

TrustedSource — global email traffic patterns and volume, network characteristics, public blacklists and whitelists.

SenderBase — global email traffic monitoring from IronPort.

Page Load Speed Check

Alertra — check the status of a web server.

Traffic Rankings

Alexa — Internet traffic rankings.

Statsaholic — blends Alexa website traffic graphs with a lightweight ajax-enhanced interface.

Best Practices

MAAWG — a global organization focusing on preserving electronic messaging from online exploits and abuse with the goal of enhancing user trust and confidence.

DMA — help center for complying with the DMA's requirements for email authentication.

Email Labs — email marketing best practices and quick tips.

MAPS — basic list management guidelines to help avoid the most common pitfalls.

Canadian Government — Canadian best practices for sending email.

London Internet Exchange — best practices for running email lists of all types.

Spam.Abuse.net — best practices for marketers.

Panix — guidelines for promoting responsible commercial use of the Internet.

Spamcon — best practices for everyone involved in email.