Frequently Asked Questions

Here you will find answers to your frequently asked questions about our service. If you need any other information, please contact us


What is the purpose of the Deltadromeus solution?
The Deltadromeus solution has been designed with the objective of verifying, in real time, whether a given email address exists. It is intended particularly for websites that collect the email address of their visitors with an email capture form. The goal, for these websites which provide a protected content or a service in exchange for an email address, is to avoid fake emails (loss of customer, email going to spam) and even to get erroneous email addresses corrected (gain of customer). The solution blocks people who did not provide their real email address.
Does Deltadromeus send an email while processing the verification of an email address?
No, Deltadromeus connects to mail servers and simulates sending an email to make sure the mailbox really exists. But no actual email is sent.
How long does Deltadromeus take to verify an email address?
A check takes about 1 second (average observed), but it can potentially take up to 25 seconds (or more). It depends on each mail server and its availability. As the goal of the solution is to provide the response quickly (in real time), we stop the verification process if it takes longer than 30 seconds. In this case, we consider that the email address is valid (so that you do not lose this address or that you do not wrongly block this visitor), but with a low confidence score. You can customize this behavior.
Is the result of a check 100% sure?
No, some mail servers do not cooperate during verification. No technology can guarantee that an email address exists 100% accurate. In fact, for each verified email, we get a confidence score (from 1 to 100). The verification works well for most mailboxes and especially those of major ISPs like gmail or hotmail. Our goal is to help you get leads with a valid email address, but we don't want you to lose a single lead by error. Our solution is therefore configured by default to accept an email in case of doubt (with a low confidence score), rather than refusing it. If the email address cannot be verified, for any reason (non-cooperating mail server, unstable internet connection), our solution will not block the lead submission. Do not hesitate to ask us to adjust this behavior to your needs if necessary.
Are all verifications counted?
No, we do not count a verification (we do not use any of your credits) if you have already verified the same email address in the last 30 days or if it is invalid because of a format error. You can therefore use the verification tool for the same email address several times without being re-credited.
Does Deltadromeus keep email addresses?
Your data remains yours and yours only. It will never be shared or used, by any means. Email addresses are only verified and stored on our secure servers for the sole purpose of reporting to you. You can configure for how long Deltadromeus will store email addresses: ranging from 0 day (not stored at all) to 60 days max (by default). After that, email addresses will automatically be deleted from our servers.
How long are verification credits valid?
The verification credits purchased are to be consumed on demand, either with the OnDemand Email Checker or Bulk Email Checker tool, and valid for 1 year. For the OnSite Email Tester tool, this is a monthly quota.
What happens when I run out of verifications, according to my OnSite Email Tester monthly plan?
Deltadromeus is configured to protect you from losing leads. If you exceeded the number of verifications included in your monthly plan, email addresses will simply be accepted without verification. You can configure this through Deltadromeus settings. We will notify you via email so that you can upgrade your monthly plan.
What is the result of a verification?
The purpose of the verification is to give a response (either yes or no) because in the end this is what matters to make the decision to consider the address as valid or invalid; but in reality we obtain a confidence score on the existence or non-existence of an address, without ever being 100% sure. That's why the Bulk Email Checker, OnDemand Email Checker and Free Email Verifier tools provide the confidence score, in addition to the result. The confidence score allows you, if necessary, to adapt the response to your needs.
What is the confidence score?
For each verification, the solution will return a response on the validity (either 1=yes or 0=no) and a confidence score (from 0 to 100) on this result. A high confidence score on a valid verification means the email address is strongly valid, a high confidence score on an invalid address means it is strongly invalid. This confidence score is provided with the response in the Bulk Email Checker, OnDemand Email Checker and Free Email Verifier tools. So, if necessary, you can adapt your behavior according to your needs and the confidence score. The OnSite Email Tester tool is set by default to accept an email address in case of doubt (validity with a low confidence score), rather than rejecting it, as it is better for websites not to block a user whose email address is valid. This behavior can be configured.
How to adapt the response according to the confidence score?
The confidence score makes it possible to adapt the result (either yes or no) of the verification according to your needs. This is only useful for cases where the confidence score is low:
  • If you prefer to accept an email address in case of doubt, you can use the result without worrying about the confidence score. This is the case, for example, if the tool is used to accept registrations for your service. You want to block any wrong address, but if in doubt, you don't want to block users and prefer that they sign up anyway.
  • If you prefer to reject an email address in case of doubt, you can use the confidence score to adapt the result: if the result is positive but with a confidence score lower than 70%, you can reject the address and consider it as invalid.
Does your solution handle greylist type cases or those requiring the actual sending of an email?
No, the tool is designed to obtain a very quick (less than a second on average) response (yes or no) in order to authorize or not a registration or an action associated with an email address. An email server that imposes the greylisting mechanism does not allow us to obtain the response in real time (a second check must be carried out several hours after the first), and we do not send any email to the addresses provided (some servers do not cooperate and claim that an email address exists even if it does not, or reveal its non-existence only after an actual email has been sent). For these cases, the solution will provide a quick, positive response (the email seems to exist, the corresponding server too), but the confidence score will be low.
Is it possible to have a trial version in order to check the correct functioning?
By registering, you will have access in your account to a documentation which explains the use of each tool and above all you will be able to activate a free trial version to carry out your tests. Tip: during your tests, if you simply want to test the sending / receiving with the API, for example, use the same test email address so as not to consume your free credits (since an already tested address is not re-credited within a 30 days period). Modify the email address only when you really want to test the validity of the address.
I can not find my confirmation email
After registration you will receive an email with a confirmation link. If you can not find it, check your Unwanted messages folder and make sure you entered a valid email address ;)
Is the API of the OnDemand Email Checker solution compatible with our programming language?
Yes, the API is compatible with any language, since it is only a simple web call that retrieves the result in the desired format (xml, json or txt).
Should I pay attention to space characters at the beginning or end of an email address?
If you check an email address that begins or ends with space, non-breaking space, or newline characters, it's not strictly a valid email address. But since the result is obviously expected for the email address without those spaces, our tool will perform the check on the email address cleaned of those characters.
How does the Deltadromeus OnSite Email Tester solution work on my website?
Once installed on your website, Deltadromeus will verify every email address entered trough your submission forms. When a valid email address is entered, the submission will go as usual. If an invalid email address is entered, a message will be displayed encouraging the user to submit a valid email address.
In which country is your solution hosted? Who is the hosting company?
Although our company is French, the service is international and our server is currently located in Canada. It is hosted by the French company OVH.
Do you collect personal data during verifications? Are you enriching a database? Do you share this database with partners?
We only collect the IP of the caller (that of your server when using OnDemand Email Checker). We do not enrich any database, we do not sell or share any data. The email to verify is only used during verification process. We obviously consider that the email addresses belong to you and we do not use it (we do not sell it, we do not share it). We store the email address only for your reporting, so that you can check in your account which email is valid or not, when it was verified, and the volume of emails checked during a period. Beyond 2 months, the email address is automatically deleted (it is anonymized) so that we do not keep any personal data. You can change the default setting in your account so that the email and / or the IP is anonymized upon registration for reporting: thus no personal data will ever be stored. The tool will return the verification result to you without ever keeping any trace of the email address. In the reporting you simply won't see the details of each verified address.