Expected Accuracy and Edge Cases
Learn what level of accuracy to expect from CSVgo, what email verification can and cannot determine, and how edge cases are handled transparently.
Email verification is not binary. It is a probabilistic process based on technical signals that vary across providers, domains, and infrastructure.
This page explains what accuracy you can realistically expect from CSVgo and how edge cases are handled.
What “Accuracy” Means in Email Verification
Accuracy in email verification does not mean certainty.
It means:
Minimizing false positives (marking bad emails as good)
Minimizing false negatives (discarding good emails)
Being conservative when signals are unclear
Preserving transparency instead of guessing
CSVgo is designed around these principles.
What CSVgo Is Highly Accurate At
CSVgo is very reliable at identifying:
Clearly invalid email addresses
Malformed or syntactically invalid emails
Undeliverable mailboxes with strong negative signals
Many catch-all emails with strong positive or negative indicators
These outcomes are based on consistent, repeatable signals.
Where Uncertainty Can Exist
Some email environments intentionally limit visibility.
Uncertainty can occur when:
Domains are configured as catch-all
Secure email gateways mask mailbox behavior
Servers suppress or delay bounce responses
Mail routing is intentionally opaque
Temporary network or server conditions interfere
In these cases, perfect certainty is not technically possible.
How CSVgo Handles Uncertainty
When CSVgo cannot determine deliverability confidently, it does not guess.
Instead:
The email is marked as risky
It is kept visible in the results
It is excluded from deliverable exports unless you choose otherwise
This ensures accuracy is not inflated artificially.
Why Some Deliverable Emails Can Still Bounce
Even emails marked as deliverable can bounce later due to:
Policy changes on the recipient side
Temporary server conditions
Email verification evaluates recipient-side readiness, not sender-side behavior.
Why Some Undeliverable Emails Might Appear Reachable
In rare cases:
A server may temporarily accept mail
A mailbox may be deactivated after verification
Routing behavior may change
These are environmental changes, not verification failures.
Why CSVgo Does Not Guarantee Perfection
Email infrastructure is dynamic by design.
CSVgo does not:
Convert unknowns into false certainty
Instead, it aims to:
Reduce risk where possible
Preserve trust in the data
Let users make informed decisions
Best Practices for Using Results
For optimal results:
Send deliverable emails first
Segment or test risky emails at low volume
Monitor bounces and replies
Adjust sending strategy based on real outcomes
CSVgo provides the data. Strategy determines results.
CSVgo provides high-confidence verification by:
Using multiple technical signals
Avoiding single-point assumptions
Marking uncertainty transparently
Reducing false positives and negatives
Edge cases exist in all email systems. CSVgo handles them conservatively and visibly, not silently or optimistically.
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