How It Works:

Here’s how SafeToSend corrects complex errors and protects your file from toxic addresses.

Step 1: CHECK

Check - Email Validation

To make sure it’s deliverable, we:

  • Determine whether the address syntax conforms to RFC (822, 2822, 5322, 3696, 5233, 6530) and FreshAddress standards.
  • Check each address in real time to confirm that the upper and lower domains and associated MX (mail exchanger) records are valid and can accept mail.
  • Ensure address meets ISP-specific requirements.
  • Verify the account is linked to an actual working mailbox. (Our proprietary algorithm for this process includes a vast database of recent email deliverability findings and a real-time SMTP check.)


Correct - Email Validation

To maximize the number of safe, deliverable addresses on your list:

  • Our patented spell-check technology corrects as many as seven errors in a single address and fixes any typos, including:
    • Misplaced or transposed @ signs and invalid characters such as spaces or quotes.
    • Typos in both TLD’s (.com, .net, .edu, etc.) and LLD’s (gmail, aol, Hotmail, etc.)
    • ANY misspelled domain, not just the most popular ones.
  • Our proprietary algorithm will also suggest alternative domains for uncommon entries (such as instead of
  • Every corrected email addresses included in your file is 100% guaranteed to be valid and deliverable.


Protect - Email Validation

We check each email address against our vast knowledgebase to identify and flag for removal any damaging (but deliverable) email addresses, including:

  • Toxic: Spamtraps and honeypots.
  • Undesirable: Frequent complainers, role accounts, disposable domains, fictitious and malicious email addresses, client-specific suppressions.
  • Not best-practice: DMA “Do Not Email List” and FCC wireless domains.