Bulk Email Verification

Email Verification Speed

How fast can MillionVerifier verify emails?

Tamas Ham-Szabo image Written by Tamas Ham-Szabo
Back to articles Tamas Ham-Szabo image Written by Tamas Ham-Szabo

Email Verification Speed

Default Speed

MillionVerifier's default speed for bulk email verification is 3,000 emails/minute + re-verification, generally taking up to 45 minutes. This means:

  • 10,000 emails are verified in 4-49 minutes.
  • 100,000 emails are verified in 33-78 minutes.
  • 1,000,000 emails are verified in approx 6 hours. 
  • 4,000,000 emails are verified in approx one day.

We verify any files with the above speed:

  • CSV, XLSX files uploaded,
  • copy-pasted email lists,
  • lists imported from any email service provider.

Speed Deceleration

Any files that contain emails from primarily one or two domains are being automatically slowed down to protect the reputation of our system and be able to maintain accurate results. Such declaration only affects 5-10% of the files but it is critical to protect our reputation for the other 90-95% of the files.


Suppose too many emails are verified from a single domain in a short period. In that case, it can damage our reputation, which will cause a higher level of unknown emails and false-negative results.

If your file contains email addresses mainly from 1-2 domains, your file may be slowed down by 90%. 


Higher Speed Requirements

If you need to verify large databases regularly, it is possible to increase the default 3,000 emails/minute speed. However, such cases are assessed individually and may be declined. If you believe you need a higher rate, please get in touch with our support team and explain why you need to verify at a higher speed.

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