SPF SPF Manager
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Knowledge Platform

SPF knowledge that actually helps

Clear answers on SPF records, lookup limits, providers, and deliverability — before you change DNS.

Featured guides

Deliverability

SPF and Email Deliverability

Correct SPF improves deliverability by giving receivers a trusted signal that your mail comes from authorized infrastructure.

Beginner 7 min read

Google Workspace

Google Workspace SPF Setup

Google Workspace uses include:_spf.google.com to authorize Gmail and Google Apps SMTP infrastructure for your domain.

Beginner 6 min read

Best Practices

SPF Record Validation

SPF record validation checks syntax, duplicate policies, lookup limits, and real-world resolution before you rely on a record in production.

Beginner 6 min read

Microsoft 365

Microsoft 365 SPF Setup

Microsoft 365 requires include:spf.protection.outlook.com in your SPF record to authorize Exchange Online outbound mail.

Beginner 6 min read

Email Authentication

What is SPF Email Authentication?

SPF email authentication lets domain owners publish which servers may send mail using their domain, helping receivers detect spoofing.

Beginner 6 min read

Browse by category

SPF Basics

Foundational SPF concepts every administrator should understand.

4 articles

DNS

How DNS, TXT records, and lookups power SPF.

7 articles

Providers

SPF guidance for common email platforms and vendors.

6 articles

Troubleshooting

Diagnose PermError, lookup limits, and broken chains.

3 articles

Deliverability

Keep legitimate mail out of spam folders.

1 articles

Microsoft 365

SPF for Exchange Online and Microsoft 365 tenants.

1 articles

Google Workspace

SPF for Gmail and Google Workspace sending.

1 articles

Security

Authentication, spoofing, and abuse prevention.

0 articles

Business

Operational and commercial impact of SPF decisions.

0 articles

Best Practices

Maintainable SPF operations over time.

4 articles

Email Authentication

SPF alongside DKIM, DMARC, and related standards.

3 articles

Future Modules

Upcoming authentication capabilities in SPF Manager.

0 articles

Latest articles

DNS

DNS Lookups in SPF

DNS lookups are the queries receivers perform to fetch SPF policies and resolve hostnames to IP addresses during authentication.

Intermediate 6 min read

Providers

SPF Email Providers

Email providers publish SPF include hostnames or IP ranges that you must add to your domain policy to authorize their outbound mail.

Beginner 6 min read

Providers

Provider SPF Synchronization

Provider SPF synchronization keeps your DNS policy aligned with the email services your organization actually uses.

Intermediate 7 min read

Best Practices

Keeping SPF Synchronized

Keeping SPF synchronized means updating DNS whenever senders, vendors, or infrastructure change so authentication stays accurate.

Intermediate 7 min read

SPF Basics

RFC 7208: The SPF Standard

RFC 7208 is the Internet standard that defines how SPF records are published, parsed, and evaluated by receivers.

Advanced 9 min read

Best Practices

Managed SPF Include

A managed SPF include centralizes provider authorization in one maintained hostname so your domain stays within lookup limits.

Intermediate 6 min read

Deliverability

SPF and Email Deliverability

Correct SPF improves deliverability by giving receivers a trusted signal that your mail comes from authorized infrastructure.

Beginner 7 min read

Best Practices

SPF Flattening Explained

SPF flattening replaces nested includes with explicit IP mechanisms to reduce DNS lookups and avoid the ten-lookup limit.

Advanced 8 min read

Google Workspace

Google Workspace SPF Setup

Google Workspace uses include:_spf.google.com to authorize Gmail and Google Apps SMTP infrastructure for your domain.

Beginner 6 min read

DNS

MX Records and SPF

The SPF mx mechanism authorizes IP addresses of the domain's MX hosts, linking inbound and outbound mail DNS in specific scenarios.

Intermediate 6 min read

DNS

DNS Propagation and SPF

DNS propagation delays can cause temporary SPF failures after you publish or update TXT records.

Beginner 5 min read

SPF Basics

SPF ip4 and ip6 Mechanisms

SPF ip4 and ip6 mechanisms authorize explicit IPv4 and IPv6 addresses or CIDR ranges without additional DNS lookups.

Intermediate 6 min read