Google quietly removed _netblocks3.google.com from its SPF record chain in early 2026, with no official announcement. For most Google Workspace users, nothing changes. But for domain owners or IT teams who manually hard-coded Google's internal SPF structure, this update is a signal to audit their records now, before a messy configuration causes a deliverability problem.
What Google Actually Changed
When you look inside Google's _spf.google.com reference, it points to internal sub-records that contain Google's IP ranges for sending email. Previously, the chain included three of these sub-records. Google has now silently removed _netblocks3.google.com from that chain, which simply means the sub-record no longer holds active sending addresses. In plain terms, Google cleaned up its SPF structure.
Google made no loud announcements about this because, for most domains, nothing breaks. The problem only surfaces if you manually copied Google's internal structure, which could leave your SPF record invalid or pointing to an unnecessary reference. It may not break email delivery immediately, but it makes your SPF setup harder to maintain.
Who Is Actually at Risk
Most Google Workspace users do not need to worry about this change. They rely on the standard include:_spf.google.com entry, and Google manages everything behind the scenes. Records in this format continue to work exactly as expected.
Those using Google's recommended include will face no issues. However, domain owners who manually copied Google's internal structure may encounter problems. This typically happens when a technical team hit the 10 DNS lookup limit and tried to resolve it by hard-coding individual netblock references instead of using an SPF flattening tool.
That lookup limit is not a minor concern. Per RFC 7208, SPF evaluation is capped at 10 DNS mechanism lookups and 2 void lookups per check. Exceeding either limit produces a PermError that fails authentication for every message from the domain. And that failure is silent: your emails do not bounce, they simply land in spam or get rejected without any clear error the sender can see.
The DNS Lookup Budget Problem
This update also highlights a wider issue for businesses using multiple sending tools. Google's include:_spf.google.com alone uses 4 of your 10 available lookups, leaving only 6 for all other senders. If you also use SendGrid, which consumes 5 lookups, the combined total reaches 9, and adding just one more sender hits the wall.
A domain that includes Google, Microsoft, SendGrid, and Mailchimp together reaches 12 lookups. RFC 7208 caps evaluation at 10. The receiving mail server returns a PermError and every message from the domain fails SPF authentication, regardless of which sender it actually came from.
For growth teams running campaigns through a marketing platform while also sending transactional email from a third service, this is a real and common trap.
What to Check in Your SPF Record
If you see individual netblock entries such as _netblocks.google.com, _netblocks2.google.com, or _netblocks3.google.com in your record, remove them. Replace all of them with a single include pointing to _spf.google.com, which keeps your configuration clean and automatically updated by Google.
If you use only Google Workspace to send email, the correct record is: v=spf1 include:_spf.google.com ~all
Checking your SPF setup every few months to spot outdated entries, duplicated references, or broken includes helps prevent alignment issues and deliverability problems.
Why This Matters for Email Marketing ROI
SPF is not just a technical hygiene task. It sits at the foundation of your sender reputation. Without a properly configured Google Workspace SPF record, your emails may get flagged as spam by receiving servers that cannot verify your domain. Your domain or IP address can get blocklisted, making deliverability recovery significantly harder than setting up authentication correctly in the first place. And your domain reputation accumulates damage as spam complaints compound over time.
Google's bulk sender requirements, announced in October 2023 and enforced from February 2024, require any domain sending 5,000 or more messages per day to Gmail addresses to authenticate with both SPF and DKIM, publish a DMARC record of at least p=none, keep spam complaint rates below 0.3%, and include a one-click unsubscribe header on marketing mail. These rules apply to every domain in the From header, and Google now rejects or routes to spam any message from a non-compliant bulk sender.
Getting this wrong directly cuts your deliverable reach, which means lower open rates, lower click-through rates, and lower return on every campaign you send.
Three Steps to Take Now
SPF alone is not enough. Combining it with DKIM and DMARC gives receiving servers the ability to verify messages correctly and block phishing attempts using your domain. Tools like SPF lookup checkers, DMARC analyzers, or email security dashboards help you monitor changes and detect configuration issues early.
To act on this update:
- Look up your current SPF record using a tool like MXToolbox or Google's Admin Toolbox.
- If your record contains only
include:_spf.google.com, no changes are needed. Google manages updates for you. - If you see any individual
_netblocksentries, consolidate them and verify your total lookup count stays below 10.
Google's quiet cleanup of its SPF chain is a reminder that email authentication infrastructure changes without warning. Domains that rely on manually constructed records will keep running into this problem. Using official include references and reviewing your setup regularly is the straightforward way to stay protected.
