FAQs#
Service Speeds#
What can affect speeds from Global Email?#
The location of the client server.
The distance between our server to yours will make a difference in overall speed. See here for our current server location list: https://www.melissa.com/company/server-locations-uptime
The current load of our public cloud servers.
We maintain and make available a large amount of processing capacity. However, all things being equal, the more usage at any given time will decrease overall speed during that time.
Mail (MX) Server responsiveness.
Premium requests will wait for a response from an MX server. If there are issues with a domain then processing may take longer.
Premium vs Express.
Premium will have slower processing speeds since it will perform a live check against an MX Server. The TimeToWait option can dramatically affect latency with premium checks. TimeToWait should be customized to meet your throughput needs.
WhoIsLookup.
Enabling this option will perform domain information lookups which has a small performance impact.
Throughput Speeds#
When to use real-time vs. batch processing#
Real-Time (Single Request)
Customer onboarding
CRM data entry
Checkout or form entry
Validation of a single email
Batch
Processing a spreadsheet or database
Processing historical data
Scheduled processing
ETL transformations
What speeds can you expect?#
Real-Time Speeds#
Response times can vary, but the majority of requests should fall between:
Express: 50 – 200 ms.
Premium: 1000 – 2000 ms.
Batch Speeds#
Single-Threaded#
A single-threaded batch process is recommended when:
Fast development is a priority.
Processing small to medium-sized lists (less than 50,000 records).
Expected processing speed is:
Express: 15,000 – 25,000 records per hour.
Premium: 4,000 – 10,000 records per hour.
Multi-Threaded#
Multi-threading involves sending multiple requests to the web server simultaneously and handling responses as they are returned. This approach can significantly improve performance by reducing the overall time required for processing.
A multi-threaded batch process is recommended when:
Processing large volumes of records quickly.
Handling large lists (more than 100,000 records).
We recommend starting with 10 threads to avoid rate limiting errors.
Expected processing speed is:
Express: 150,000 – 250,000 records per hour.
Premium: 40,000 – 100,000 records per hour.
Note
A single-threaded process remains a viable option for processing larger lists, though it may take longer compared to a multi-threaded approach.
Scaling and Rate Limiting#
Melissa utilizes dynamic scaling to improve throughput speeds during peak usage periods. This behavior ensures that our web services can adjust to changes in traffic and consistently provide optimal performance regardless of demand.
To maintain service stability and prevent excessive load, Melissa enforces rate limiting based on request volume and frequency. For more information, please refer to our rate limiting page: Rate Limiting.
Service Summary#
What are the abilities of the service?#
Ability |
Description |
|---|---|
Service Availability |
99.99% |
Recommended Timeout |
13s |
HTTPS |
Yes |
Batch |
|
Protocols |
|
Token Server |
Yes |
Multithreading |
Yes |
Recommended Threads |
5 |
Unicode Detection |
Yes |
Valid |
Yes |
Accept All |
Yes |
Unknown |
Yes |
Invalid |
Yes |
Tech Support |
Yes |
Syntax |
Yes |
Domain |
Yes |
Mailbox |
Yes |
DNS A |
Yes |
DNS MX |
Yes |
B2B Domains |
Yes |
B2C Domains |
Yes |
Spam Trap Detection |
Yes |
Block List |
Yes |
Role or Disposable |
Yes |
Typo Correction |
Yes |
Illegal Character |
Yes |
Features#
What Features Does Global Email Have?#
Capabilities#
Global Email validates your email address information and will allow your Web sites and custom applications to update email addresses in your database files while verifying and correcting misspelled domain names.
You can use Global Email to:
Verify and correct syntax errors in an address, checking for illegal characters and extra @ characters
Verify and correct top-level domain names
Check for and correct, misspelled domain names
Check for and correct, domains that have changed
Standardize casing in email addresses
Perform Real-time Mailbox Validation
Sender Blacklist Caution
Pace email delivery based on confidence scores
Extended Functions#
You can validate quickly using our database, or if speed is not as important, you can validate realtime.
Global Email Real time Mailbox Validation has the ability to detect:
The email account (the inbox) does not exist at the given domain
The email address format is incorrect
If mailbox exists on mail server
Invalid, bad email
Pending Mailbox
MX Server Error
The email address is associated with a domain that doesn’t exist
Unknown or catchall domains
Disposable domains/Spamtrap domain, Email address is disposable and the Inbox will self-destruct
Role-based emails
Valid email address
Deliverability Confidence Scores
Predictive Accept-All Validation. Predict the likelihood of an accept-all email being deliverable. Reflected by the Deliverability Confidence Score.
What is the difference between Email Validation in Global Email vs Personator Consumer?#
Global Email leverages everything we know about email syntax and mailbox validation to provide the most accurate and actionable deliverability data. Real-time mailbox validation empowers users to make informed marketing decisions that protect your web reputation, increasing the efficacy of your marketing campaigns and maintaining key lines of communication with your customer base.
Personator Consumer implements a subset of Global Email’s features. The first step in email validation is determining correct syntax and a valid domain. Personator Consumer accomplishes this, and can apply many of the same flags as Global Email, but only if a recent validation for an email exists in our cache of validated emails. Lightning-fast lookups provide actionable deliverability data when receiving email addresses on forms or cleansing your contact database.
For user registration and basic validation needs, Personator Consumer cleanses email addresses alongside your other contact data seamlessly.
For marketing campaigns and ongoing email list maintenance, Global Email is an asset that will help you ensure campaign efficacy now and in the future by protecting your web reputation from the negative effects of hard bounces, spamtraps, mobile domain rules, and more. Leverage real-time validation to check email addresses at the mailbox level, ensuring higher recipient engagement. Keep implementation and business logic simple using the Deliverability Confidence Score and learn more about email domain registrants with WhoIs domain information.
Feature |
Personator |
Global Email |
|---|---|---|
Real-time Mailbox Validation |
✓ |
|
Lightning-fast Cached Mailbox Validation |
✓ |
✓ |
Deliverability Confidence Score (for Marketing) |
✓ |
|
Breached Email Indicator (for user intelligence) |
✓ |
|
WhoIs Domain Registrant Lookups (organization intelligence) |
✓ |
|
No additional cost when cleansing addresses, phones, or names |
✓ |
Supported Protocols#
What protocols does Global Email support?#
Global Email is a RESTful API (Single and Batch) available in two formats:
JSON (Single, Batch)
XML (Single, Batch)
It is also available as a component:
Microsoft SSIS Component
Required Fields#
What are the required fields?#
Required:
CustomerID
Email
Optional:
RecordID
TransmissionReference
Options
Deliverability Confidence Score#
What is the deliverability confidence score and how do I use it?#
Deliverability confidence score was added to Global Email V4. It is intended to be a quick and simple way to interpret and use our results. Please see Deliverability Confidence Score (Basic) for more information.
DCS Usage and Risk-Averse Strategies#
The Deliverability Confidence Score (DCS) helps users implement risk-averse email validation strategies by providing a graded assessment of an email address’s likelihood of successful delivery. You can use this score to fine-tune email delivery policies and reduce the risk of bounces.
For a conservative approach, you may choose to set a higher DCS threshold, sending email blasts or marketing materials to only emails with strong deliverability indicators while filtering out borderline cases, such as Accept-All addresses with uncertain histories. If too many bounces occur, adjusting the threshold upward can further refine deliverability by excluding more questionable addresses. Normally, we recommend mass mailing only to emails with a 61+ DCS score. For a risk averse strategy, you might consider adjusting this threshold to 70 or more.
Conversely, if you need broader coverage, you can lower your threshold to include more emails but should monitor bounce rates and adjust as needed. This can be a good idea if you have positive indicators about your email data that correlate with a higher deliverability rate. Generally, we don’t recommend lowering this threshold below 61.
By leveraging Predictive Accept-All Validation and other DCS-driven insights, businesses can strike the right balance between reach and reliability in their email campaigns.
Predictive Accept-All Validation#
Our Predictive Accept-All Validation enhances the Deliverability Confidence Score (DCS) by improving accuracy for Accept-All domains, which appear to accept all emails sent, but may later reject undeliverable ones.
To address this, Melissa analyzes historical validation data, domain-specific intelligence, and other trend data to predict whether an Accept-All email is truly deliverable. By incorporating these insights, the DCS provides a more reliable assessment, reducing false positives and helping users make informed decisions about Accept-All email addresses.
Result Codes#
What are result codes?#
Our result codes allow you to evaluate emails at a more granular level of detail. All the information represented by result codes is encapsulated in the Deliverability Confidence Score, but some may wish to dive deeper.
While we recommend most users look to the Deliverability Confidence Score, certain power users, such as those who need to pass on granular information to their own clients, will be able to use result codes to great effect.
Global Emails uses two types of result codes: status (ES) and error (EE). ES codes are returned if the email is valid, or was fixed and made valid, and they also give more information about the exact type of email (disposable, mobile, etc.).
Any EE code means the email is in some way invalid. Since we have removed the old result code ES02 from Version 4, invalid emails will only have EE codes and either ES21 or ES22.
For more information on our result codes and how to use them, please refer to Result Codes (Advanced).
What are some examples of input that returns specific codes?#
Code |
Short Description |
Example Input |
|---|---|---|
ES - Email Status |
||
|
Valid Email |
|
|
Unknown Email |
|
|
Mobile Email Address |
|
|
Disposable Domain |
|
|
Spamtrap Domain |
|
|
Syntax Changed |
|
|
Top Level Domain Changed |
|
|
Domain Changed (Spelling) |
|
|
Domain Changed (Update) |
|
EE - Email Error |
||
|
Email Syntax Error |
|
|
Email Domain Not Found |
|
|
Email Server Not Found |
|
|
Invalid Email |
|
Mailbox Validation#
Why should I use email validation?#
To reduce bounce rates (rejection) and avoid being labeled a spammer from mail servers. Once you are blacklisted, your email deliverability campaigns will suffer a lot and you have trouble sending out emails in the future (most mail servers subscribe to a form of spammers list). Integrators should consult with us to in order to understand what they need to look out for to avoid a bad campaign and why certain emails should be flagged/inspected. Even if you avoid spam traps, sending out too many invalid emails will cause the mail server to flag you as a potential spammer (which is why mailbox validation is important).
What is an accept all mail server?#
Accept All means that the server stated all emails queries are considered active and valid regardless if they actually are. It is a setting by the responding mail server and we have no way to know if the email actually exists or not. We only know that the responding server says that the email exists regardless if the email actually exists on its server. It is up to you to decide whether or not to risk sending the emails out. Accept All emails generally have a higher bounce rate.
What is the difference between mailbox and normal email validation?#
Currently, our email object only performs normal email validation which is essentially just a simple spell check, mail server and domain check. Our Global Email Web Service does both mailbox and normal email validation. Mailbox validation means that the mailbox in the mail server is actually active and exists.
What is mailbox validation?#
Mailbox validation is more comprehensive beyond than a MX Domain check. Mailbox validation actually asks the mail server to see if that mailbox account is active and if it exists. Otherwise we will only check to see if the mail server is active and if the mail server exists.
Why does an email have no mailbox validation?#
Mailbox validation will only occur if the email passes our domain level and syntax level checks.
What does mailbox validation do?#
It performs what is known as an SMTP check in the industry. Our service avoids being labeled as spammers for performing this check through proprietary technology. Your emailing reputation will be safe since we are the ones doing the mailbox checks for them. Of course, your emailing reputation will depend on our results when you start your email campaign on your end.
What does confidence level mean?#
ES22 means that we performed a mailbox check on this email. When we say confidence level, we mean the certainty of the result code we are getting back. For example, ES01, ES22. Means that “with high certainty, this email is an valid email”. These ES2x are the identifiers for our mailbox validation calls. Otherwise, we can’t keep count of performed mailbox validation calls. So to summarize, the ES2X dictate how certain we are of the ES codes coming back.
ES23 is reserved for unicode detection for emails. We do not have UTF-8 Support yet for validating these emails. So for now we just identify these unicoded emails.
Verify Mailbox Options#
TimeToWait Option#
What exactly does the TimeToWait Option do? What number should I be using?#
TimeToWait is our newest option designed to give you more control over the process flow. It’s up to you and your team to decide if this option is necessary for you to use. The minimum value for this option is 5 seconds, while the maximum value is 45 seconds. The Default value is set to 25 seconds. Setting TimeToWait to a lower number will give you faster, but less accurate results. On the other hand, setting this value to a higher number will give you slower, but more accurate results. It’s up to you and your team to decide what you value more for each project – accuracy or speed. We recommend running a small test batch with a large variety of your emails at different TimeToWait settings. Every ‘ideal number’ will be different; and may change dependent on your email batch. The best way to find your ‘ideal number’ is to get a good spread across your email data base, and test that sample selection at different TimeToWait settings until you find the number that gives you the most accurate results in an acceptable time.
For more information, see ES03’s and TimeToWait.
ES03’s and TimeToWait#
ES03’s can happen for a wide variety of reasons. One of them being the particular email timed out. We can reduce the number of ES03’s by increasing the length of time before the system will give up on an email and move on to the next. The ‘ideal’ number to use for TimeToWait will change primarily based on your email batch. For example, if you are validating email domains from a small to mid-sized business type you may want to consider increasing your TimeToWait. While on the other hand, if you are validating emails from large mailbox providers or companies you may consider decreasing your TimeToWait.
Recommended TimeToWait
Our research and analysis shows that the TimeToWait option results show varying levels of accuracy. Be warned that your results may vary with your own dataset. For example, the default time of 25 seconds you can expect receive around 7% unknowns. If you change this to a time out of 20 seconds, you can anticipate around 13% unknowns. At the end of the day you need to determine how accurate you need your results, and how long you are willing to wait to receive them. For example, batch processing will have a higher accuracy percentage (Less unknowns) from setting a high timeout value. Meanwhile, for real time web form type of validations where speed is of the essence, a lower timeout with logic to handle any potential unknowns may be preferred. We are constantly improving our algorithm in efforts to improve both accuracy and speed, but this is one method for us to give you more control over how our system will handle your data.
‘Good’ Email#
What is a good email?#
A good email will have an ES01 result code, consists of valid characters for the mailbox name, an ‘@’ symbol, and a valid domain name. If mailbox validation option is set, a good email consist of valid characters, valid domain name, and active/existing mailbox account on that mail server (ES20 or ES21 or ES22).
Accept-all Emails#
What is an accept-all email?#
Accept-all (indicated by result code ES07) means that the email provider sets up their servers in a way that makes them relatively opaque to external email verifiers. A verifier will be able to perform a normal syntax check and determine if the domain is valid and active.
The email provider tells external verifiers that any email is valid and active, and even accepts all incoming emails as if the mailbox is valid and active, regardless of what may actually be the case. Because of this, sending emails to such addresses is essentially a gamble. We are constantly improving our accuracy with these emails.
How does Melissa verify accept-all emails?#
Our Predictive Accept-All Verification uses a proprietary, innovative method to validate accept-all emails by analyzing them for signs of historical activity. This analysis is integrated into our Deliverability Confidence Score, providing a reliable indication of whether an email to an accept-all address is likely to reach its intended recipient.
Why does accept-all get its own result code?#
Accept-all emails are generally problematic, but perhaps the most problematic for large email marketing campaigns. Without a way to identify accept-all emails, such a campaign could send a great many emails to accept-all addresses, many of which would bounce or get flagged as spam, thus decreasing ROI.
Please refer to Result Codes (Advanced) for more information on how to handle accept-all emails using Global Email.
‘Bad’ Email#
What is a bad email?#
A bad email will return an error code (EExx) which will tell you why this email is deemed to be a bad email.
‘Unknown’ Email#
What is an unknown email?#
An unknown email will return a ES03. With mailbox validation even if it’s an unknown email, we want to let you know that it’s with high certainty that it’s an unknown email and that we did try request to the mail server for a mailbox validation call on this email.
Here are some examples of unknown emails, the mail server for some reason during the mail validation call, triggered our ES03 code either by responding with a non standardized response, or the mail server is increasingly aggressive with their protection to the point where IP address block might be implemented against our system if we continue or mail server tells us that we need to send a message to receive a bounce code (actually performing this could cause IP Block) or Grey Listing technology has been detected (we could not proceed). Another possible reason, is that the mail server the email resides on is timing out. There are too many to list and some are proprietary in nature. ES03 is meant to convey “at this moment in time, the email’s status cannot be determined”, email statuses are always in flux and it could change if you were to do another check.
Some mail servers are friendly and some are hostile. We will try to do mailbox validation on all mailboxes. Hostile mail servers have been developing countermeasure technologies to fight detection services like ours. It is a constant warfare for countermeasures and detection technologies. As they constantly develop their technologies…we constantly develop ours. So sometimes, for a certain email, mail server’s algorithm at the mailbox validation level did a better job countering our algorithm’s moves which results in a ES03.
Like a chess game, the results could be different if we rematch. It is up to you whether you want to run these unknown emails again…our algorithm could perform different actions that might result in a win and you receive a definite ES01 or lose again with ES03. We implemented a 3 day wait period minimum before retrying.
Important: Unknown emails can take as long as 13 seconds to verify. If your process is time sensitive and you are not interested in unknown emails, you can timeout early and mark the email as bad or unknown yourself.
Aol and Yahoo mail servers are known to take the longest time to validate.
Privacy#
For general privacy and security concerns, see our Cloud APIs Privacy and Security page.
Does email validation data cause customer data to be sent outside of the EU?#
Yes, in some cases. Email validation may require querying MX (Mail Exchange) servers that are located outside the EU. In this case, the connection is necessary to validate the mailbox against the mail server.
Melissa takes strong measures to minimize the amount of data transmitted and protect its users’ privacy.