SPF Record for Email to Fax

What is SPF?

SPF (Sender Policy Framework) is an email authentication method that specifies which mail servers are authorized to send email on behalf of your domain. When properly configured, SPF helps prevent email spoofing and improves email deliverability.

When using IntelliVoice's email-to-fax service, fax confirmations and notifications are sent from our servers on behalf of your domain. To ensure these emails are delivered properly (and not marked as spam), you should add our mail servers to your SPF record.

How SPF Records Work

An SPF record is a DNS TXT record published on your domain. When a receiving mail server gets an email claiming to be from your domain, it checks your SPF record to verify the sending server is authorized.

SPF Record Components

• v=spf1 - Version identifier (always starts with this)
• a - Authorize the domain's A record IP addresses
• mx - Authorize the domain's mail exchange servers
• ip4: - Authorize a specific IPv4 address or range
• include: - Include another domain's SPF record
• redirect= - Redirect to another domain's SPF policy

SPF Qualifiers (Ending)

• -all - Hard fail: reject mail from unauthorized sources
• ~all - Soft fail: accept but mark as suspicious (recommended)
• ?all - Neutral: no policy statement

Determine Your Current SMTP Servers

Before modifying your SPF record, identify all services that send email on behalf of your domain:

• Your primary email provider (Microsoft 365, Google Workspace, etc.)
• Marketing platforms (Mailchimp, HubSpot, etc.)
• CRM systems that send email
• Website contact forms
• IntelliVoice eFax service

SPF Record Examples

Apple iCloud / Custom Domain

If your domain uses Apple iCloud for email plus IntelliVoice eFax:

v=spf1 ip4:17.0.0.0/8 ~all

This authorizes Apple's IP range (17.x.x.x) with a soft fail policy.

IntelliVoice eFax Servers

To authorize IntelliVoice email-to-fax servers, add these IP addresses to your SPF record:

v=spf1 mx ip4:64.136.174.217 ip4:64.136.173.84 a:titaniumvfax.com ~all

This record includes:

• mx - Your existing mail servers
• ip4:64.136.174.217 - IntelliVoice fax server 1
• ip4:64.136.173.84 - IntelliVoice fax server 2
• a:titaniumvfax.com - IntelliVoice fax platform
• ~all - Soft fail for unauthorized sources

Gmail / Google Workspace

If you use Google Workspace for email:

v=spf1 include:_spf.google.com ip4:64.136.174.217 ip4:64.136.173.84 a:titaniumvfax.com ~all

Microsoft 365

If you use Microsoft 365 for email:

v=spf1 include:spf.protection.outlook.com ip4:64.136.174.217 ip4:64.136.173.84 a:titaniumvfax.com ~all

Gmail with Redirect

An alternative approach using redirect:

v=spf1 redirect=_spf.google.com

Note: When using redirect, you cannot add additional entries in the same record. Consider using include instead if you need multiple sources.

How to Update Your SPF Record

1. Log in to your domain registrar or DNS hosting provider
2. Navigate to DNS settings for your domain
3. Find existing TXT records (look for one starting with v=spf1)
4. If an SPF record exists, add the IntelliVoice IP addresses to it
5. If no SPF record exists, create a new TXT record with the complete SPF string
6. Save your changes

Propagation Time

After updating your SPF record, allow time for DNS propagation:

• Changes can take 15 minutes to 48 hours to propagate globally
• The actual time depends on your DNS TTL (Time To Live) setting
• Lower TTL values mean faster propagation

Tip: Before making changes, lower your TTL to 300 seconds (5 minutes). After changes propagate successfully, you can increase it back to a normal value like 3600 (1 hour).

Verifying Your SPF Record

After making changes, verify your SPF record is correct using online tools:

• MXToolbox SPF Lookup
• Google Admin Toolbox Check MX
• Kitterman SPF Testing Tools

Important Notes

• You can only have one SPF record per domain
• SPF records have a 10 DNS lookup limit (includes, a, mx mechanisms count)
• If you exceed 10 lookups, the SPF check may fail
• Use IP addresses directly when possible to reduce lookup count