How-to
How vendor detection works and how to add custom vendor patterns
Understand how Blankitt attributes sending sources to known vendors, and how to add, import, export or reset your own custom CIDR/domain to vendor-name patterns.
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When you read a DMARC report, a bare IP address tells you little. Blankitt's vendor detection turns those IPs and header-from domains into recognisable sender names, so you can quickly tell a legitimate service from a spoofer and know exactly what to align.
How vendor detection works
For each sending source in a report, Blankitt maps the source IP and header-from to a known sender using:
- A built-in catalog of common email vendors — SendGrid, Mailgun, AWS SES, Microsoft 365, Google and many more.
- Your custom patterns (described below).
Where they overlap, your tenant patterns win — so you can override or extend the built-in catalog whenever it gets something wrong or does not recognise an internal/niche sender.
Attributed vendor names appear throughout the app — most usefully on the Offenders page, where they help you recognise legitimate senders that need aligning.
When to add a custom pattern
- An internal mail server or appliance shows up as an unattributed IP.
- A regional or niche ESP is not in the built-in catalog.
- You want a clearer, business-specific label (e.g. "Acme Payroll") for a known range.
Adding patterns in Settings
Go to Settings -> Vendor pattern overrides. A pattern maps a CIDR range or domain to a vendor name. For example:
| Match | Vendor name |
|---|---|
198.51.100.0/24 | Acme Payroll |
mail.partner.example | Partner CRM |
Once saved, future report processing labels matching sources with your chosen name.
Bulk managing patterns with CSV
The vendor pattern overrides section supports three CSV operations:
- Import — upload a CSV to add many patterns at once. This is ideal when migrating from another tool or managing patterns in a spreadsheet.
- Export — download your current custom patterns as a CSV, for backup or editing offline.
- Reset to defaults — clear all custom patterns and fall back to the built-in catalog only.
A typical workflow is: Export to get the current set, edit the CSV, then Import the updated file.
Each CSV row pairs a match value (CIDR or domain) with a vendor name. Export an existing set first to see the exact column layout your tenant expects.
Where changes are recorded
Vendor-pattern import and reset actions are logged on the Activity page (a local action log of changes), so you have a record of when your overrides changed.
Tip
Custom patterns only relabel sources for your convenience — they do not change DMARC pass/fail outcomes. Alignment is still decided by SPF and DKIM. Use patterns to understand your traffic faster, then fix alignment via Fix Groups.