Last updated July 10, 2020
Since we check emails on the spot, in real-time, the accuracy rate is high. Depending on the value of the email's reachability, we guarantee the following accuracies:
safe: We guarantee a hard bounce rate lower than 2%. Bounce rates may still happen, because we connect to the email's SMTP server from a different IP address than you, and yours might be blacklisted.
invalid: We guarantee with a confidence of 99% that this email is not deliverable.
risky: The email address appears to exist, but has quality issues that may result in low engagement or a bounce. We don't recommend sending to these emails, and don't commit on an accuracy rate.
unknown: It might happen on rare occasions that the email provider doesn't allow real-time verification of emails. In this case, there's unfortunately nothing Reacher can do. Please let us know if this happens, we're working on finding ways to solve these issues, which in most occasions are solved on a case-by-case basis.
It might happen on rare occasions that the email provider doesn't allow real-time verification of emails. In this case, there's unfortunately nothing Reacher can do. Please let us know if this happens, we're working on finding clever ways to work around these issues.
Hard bounces are email addresses that could not be delivered, for example due to an invalid mailbox. They are treated very seriously by most email service providers.
Reacher's backend is stateless and scalable, which means that no matter if you verify concurrently 10 or 100000 emails, the infrastructure will elastically scale to meet your needs. Bulk email validation is therefore achieved by send parallel API requests.
We are currently working on an API endpoint which accepts a list of email addresses, as well as list uploads (CSV, XLS). If these features interest you, please let us know by upvoting the feature here: https://github.com/reacherhq/backend/issues/149.
Reacher takes security and privacy seriously. It's simple, we do not store the emails you check, and we do not share your data with any third parties. The email verification is done in real-time, and once it's finished, we clear everything.
Yes, we provide an API for our email verification service. Read more about our API at REST API Documentation.
Payment can be made by Visa, MasterCard or Amex. Behind the scenes, we use Stripe Connect to process payments.
The process is fairly straightforward and outlined in the telnet script below.
We first form a connection to the mail server with a basic TCP connection on port 25. We then identify ourselves as
example.comand a reply-to email of
email@example.com. The last step, and the most important in this process is the
RCPTcommand. This is where, based on the response from the mail server, we are able to conclude the deliverability of a given email address. A
200implies a valid inbox and anything else implies either an error with our connection to the mail server, or a problem with the address requested. A full outline of all the status codes we parse can be found here.
telnet mail.abccorp.com 25 HELO example.com MAIL FROM: firstname.lastname@example.org RCPT TO: email@example.com
If you can read some code, then the best is to check out Reacher's open-source code at https://github.com/reacherhq/check-if-email-exists.
I'm Amaury, an indie developer based in Berlin. Say hi to me 👋! ✉️ firstname.lastname@example.org.