Best email provider lookup tools (2026)
Quick answer: To find the mail provider of many domains without an account, SimpleVerifier's bulk email provider lookup takes up to 1,000 unique domains a run and names Google Workspace, Microsoft 365 and others, including gateways such as Proofpoint. MxToolbox and DNSChecker look up one domain's MX records at a time. Apify actors handle 5,000 to 10,000 domains a run with an Apify account, billed per 1,000 domains after the free plan's $5 a month of usage.
By SimpleVerifier Team · Last updated · Prices and limits checked on each vendor’s own site
Side by side
Ranked by the most domains one run looks up without creating an account; tools that need an account score 0.
| # | Tool | Domains per run, no account | Free limit | Bulk limit | Price | Signup needed | Best for |
|---|---|---|---|---|---|---|---|
| 1 | SimpleVerifier bulk email provider lookup | 1,000 | 5,000 rows and 1,000 unique domains a run | 1,000 unique domains a run; 1,000 domains per ten minutes per connection | Free tool (paid plans are for email verification) | No | Segmenting a lead list by mailbox provider |
| 2 | MxToolbox MX Lookup | 1 | One domain a lookup | 1 domain (bulk needs an account, below) | Free | No | One domain's MX records plus follow-on DNS tests |
| 3 | DNSChecker MX Lookup | 1 | One domain a lookup, no stated cap on lookups | 1 domain | Free | No | A quick MX record check |
| 4 | MxToolbox Bulk Lookup | 0 | Monthly quota on a free account; size not published | Not published | Free account; more lookups on paid plans (price not on the bulk page) | Yes (free MxToolbox account) | MX, blacklist and DNS checks across many IPs or domains |
| 5 | Apify: Bulk SPF, DMARC & DKIM Checker + Email Provider Finder | 0 | Apify's free plan includes $5 a month of usage | 5,000 domains a run | $2.00 per 1,000 domains | Yes (Apify account) | Developers who want provider plus SPF, DMARC and DKIM as JSON |
| 6 | Apify: MX Lookup (junipr) | 0 | Apify's free plan includes $5 a month of usage | 10,000 domains a run | $1.95 per 1,000 domains | Yes (Apify account) | Batches of up to 10,000 through an API |
How we compared
We read each tool's own page on 19 October 2026 for per-run limits, account requirements and price. A tool counts as a provider lookup if it returns MX records; we note which ones also name the provider. We did not run accuracy tests, so none is claimed.
Each tool in a few lines
1. SimpleVerifier bulk email provider lookup(our tool)
Best for: Segmenting a lead list by mailbox provider
- Names the provider (Google Workspace, Microsoft 365 and others), not just the MX host
- Flags security gateways such as Proofpoint or Mimecast in front of the mailbox
- Accepts domains, email addresses or URLs; single-domain version at /tools/email-provider-lookup
- Watch out: While a sign-in test runs, some visitors are asked to sign in (free, with Google) after 25 rows; everyone else gets the full run without an account.
Checked October 19, 2026: SimpleVerifier: Bulk email provider lookup
2. MxToolbox MX Lookup
Best for: One domain's MX records plus follow-on DNS tests
- Sits beside MxToolbox's other free DNS, blacklist and SMTP tests for the same domain
- Watch out: One domain at a time
Checked October 19, 2026: MxToolbox: MX Lookup
3. DNSChecker MX Lookup
Best for: A quick MX record check
- States no charges and no limit on the number of domains you check
- Watch out: Shows MX records; one domain at a time
Checked October 19, 2026: DNSChecker: MX Lookup
4. MxToolbox Bulk Lookup
Best for: MX, blacklist and DNS checks across many IPs or domains
- Runs MX, blacklist, DNS and other lookups on a pasted list
- Pulls domains and IPs out of pasted text; CSV download
- Watch out: Needs an account; the monthly quota does not carry over
Checked October 19, 2026: MxToolbox: Bulk Lookup tool · MxToolbox Knowledge Base: What is the Bulk Lookup tool
5. Apify: Bulk SPF, DMARC & DKIM Checker + Email Provider Finder
Best for: Developers who want provider plus SPF, DMARC and DKIM as JSON
- Mailbox provider, gateway and SPF, DMARC, DKIM in one row
- Runs through the Apify API and scheduler
- Watch out: Pay per domain on an Apify account
Checked October 19, 2026: Apify Store: Bulk SPF, DMARC & DKIM Checker + Email Provider Finder · Apify: Pricing
6. Apify: MX Lookup (junipr)
Best for: Batches of up to 10,000 through an API
- Up to 10,000 domains a run
- Provider detection plus SPF, DKIM and DMARC checks
- Watch out: Pay per domain on an Apify account
Checked October 19, 2026: Apify Store: MX Lookup (junipr/mx-lookup) · Apify: Pricing
Common questions
- How do I find out which email provider a domain uses?
- Look up the domain's MX records. Hosts ending in google.com or googlemail.com mean Google Workspace, and mail.protection.outlook.com means Microsoft 365. An email provider lookup does that matching for you and also reads SPF to spot a provider hidden behind a security gateway.
- Can I check the email provider of a whole list at once?
- Yes. SimpleVerifier's bulk email provider lookup takes up to 1,000 unique domains a run without an account. MxToolbox's Bulk Lookup needs a free account, and Apify actors take 5,000 to 10,000 a run with an Apify account, billed per 1,000 domains after its free plan's $5 a month.
- What does it mean when the MX points to Proofpoint or Mimecast?
- Those are security gateways that filter mail before it reaches the real mailbox. The mailbox itself is often still Google Workspace or Microsoft 365, which the domain's SPF record usually reveals.
- Is an email provider lookup the same as verifying an address?
- No. A provider lookup reads DNS for the domain. Whether a specific mailbox exists takes an SMTP check, which is what an email verifier does.
- Does a provider lookup contact the domain's mail server?
- SimpleVerifier's does not: it makes two DNS queries per domain (MX and SPF) and sends nothing to the mail server.