Research / Email Research / B2B Email Quality Benchmark 2026
B2B Email Quality Benchmark 2026: 1,000-Record Study
This LastDatabase study measures observable quality characteristics in a deterministic sample of 1,000 records from a 26,512,569-record B2B email dataset.
The study combines syntax, DNS, duplication and field-completeness checks with third-party validation of a predetermined 100-record subset by ZeroBounce.
Published: September 13, 2026 | Population: 26,512,569 records | Sample: 1,000 records
Key Findings
All 1,000 sampled addresses passed syntax validation. Of those records, 932 had domains publishing MX records. Another 28 had address-record fallback without MX, while 40 had no qualifying mail DNS result during the benchmark.
No duplicate email rows were detected within the deterministic 1,000-record sample.
A predetermined 100-record subset was locked before external validation. ZeroBounce later classified 95 records as Valid, four as Invalid and one as Abuse.
1,000-Record Internal Benchmark
| Measurement | Records | Rate |
|---|---|---|
| Email present | 1,000 | 100.0% |
| Syntax valid | 1,000 | 100.0% |
| MX published | 932 | 93.2% |
| Address-record fallback | 28 | 2.8% |
| No qualifying mail DNS | 40 | 4.0% |
| Duplicate email rows | 0 | 0.0% |
Field Completeness in the 1,000-Record Sample
The benchmark also measured whether selected B2B fields contained values in the sampled records. These percentages measure field presence, not the factual accuracy of each value.
| Field | Records Present | Coverage |
|---|---|---|
| Company name | 971 | 97.1% |
| Company website | 801 | 80.1% |
| Job title | 758 | 75.8% |
| Industry | 796 | 79.6% |
| Country | 983 | 98.3% |
| Source | 1,000 | 100.0% |
| Created at | 1,000 | 100.0% |
| Updated at | 1,000 | 100.0% |
Third-Party Validation of the Locked 100-Record Subset
Before third-party validation, 100 records from the benchmark sample were predetermined and locked. This prevented the subset from being changed after seeing the validation results.
95 of 100 predetermined records received a “Valid” status from ZeroBounce.
| ZeroBounce Status | Records | Rate |
|---|---|---|
| Valid | 95 | 95.0% |
| Invalid | 4 | 4.0% |
| Abuse | 1 | 1.0% |
All four records classified Invalid carried the ZeroBounce
sub-status does_not_accept_mail.
Sampling Methodology
The benchmark population contained 26,512,569 B2B email records. LastDatabase selected a deterministic pseudorandom sample of 1,000 records across the complete ClickHouse table.
Selection used ClickHouse sipHash64 with the fixed seed:
lastdatabase-b2b-email-pilot-2026-v1
The deterministic method makes the selection reproducible from the same underlying dataset and selection procedure. The 100-record external-validation subset was committed before its results from ZeroBounce were known.
What the DNS Results Mean
An MX result means the email domain published one or more mail exchanger records when tested. In this sample, 932 of 1,000 addresses were associated with domains publishing MX records.
Another 28 addresses were associated with domains that had no MX result but had an A or AAAA address record. SMTP permits this type of address fallback, although it is weaker evidence of mail handling than an explicit MX record.
The remaining 40 records had no qualifying mail DNS result during the benchmark.
Evidence Integrity and Reproducibility
SHA-256 hashes were recorded for the frozen benchmark evidence. They provide integrity references for the study artifacts without publishing the email-level private sample.
| Evidence Artifact | SHA-256 |
|---|---|
| Public pilot report | 670cda708d4d068a308630b91153420650848676d21460fc63b7e4bda88884bd |
| Pre-validation commitment | 27d63b215dc148a3d16871111010bdbbcd59c84dad5b6783bbf8b0a93dd6c4aa |
| Locked external-validation subset | f4190fe4888b3f5dab5515ffdfa3c6fcc5f7c21cdbf9a78e1ba5e7875694c0b6 |
| ZeroBounce raw validation package | 24411fc1bff4f3aa87f9ee02d3a9999e2ebbabec1494bbb5977a3a9178fdad66 |
| ZeroBounce all-results CSV | ead30636cdf5b965cd0a06dd19de970ee9708eba7dd5b4b8b1a08dab0508b5a6 |
| External-validation summary | 496b523e56dfdc10dec565bf29da0020167be8862a327d5d705f5e38434ae18a |
Email-level samples and the raw third-party validation package remain private. They are not exposed through this public research page.
How to Interpret This Research
This benchmark is intended to make specific, reproducible measurements visible rather than convert several different quality signals into one unsupported accuracy percentage.
Syntax, DNS configuration, field completeness and third-party email validation answer different questions. They should be interpreted separately when evaluating B2B contact data.
Related LastDatabase Research
For broader statistics about the structure and coverage of the LastDatabase B2B email dataset, see the Email Data Profile 2026 .
You can also visit the LastDatabase Research Center for additional data studies and methodology reports.