Mailjet Email Verification
Integration
Connect your Mailjet account to ValidEmailChecker and verify your contact lists without file exports, manual uploads, or spreadsheet gymnastics. Whether you are sending transactional emails or marketing campaigns, clean lists mean better inbox placement and a healthier sender reputation.
Connect Mailjet
Enter your API Key & Secret
Connection Name (optional)
Mailjet API Key
Mailjet API Secret
Where to find:API → API Key Management → Copy API Key & Generate Secret Key
What You Need to Get Started
Mailjet Account
Free or paid — both work.
API Key & Secret
Found in API Key Management.
Verification Credits
1 credit per email. 200 free on signup.
60 Seconds
Paste both keys and you are connected.
Finding Your Mailjet API Credentials
Mailjet requires both an API Key and an API Secret. Here is how to find them.
How to find your credentials:
Open API Key Management
Log in to Mailjet. Click API in the left sidebar, then select API Key Management. Your Primary API Key is listed here.
Get Your Secret Key
Click the settings icon next to your API Key to view or reset your Secret Key. Copy both values — you will need them both to connect.
You will need both:
API Key
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The public identifier for your account
API Secret
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The private key — proves it is you
Save Your Secret Key Immediately
Mailjet only shows your Secret Key once when it is generated. Copy it immediately and store it somewhere safe. If you lose it, you will need to reset it — which generates a new one and invalidates the old one.
How to Connect Mailjet
The entire setup takes under a minute. Here is exactly what to do.
Get Your API Key and Secret
Log in to your Mailjet account. Click API in the left sidebar, then select API Key Management. Your Primary API Key is listed here — copy it. Click the settings icon next to your key to view or generate the Secret Key. Copy both values — even a small typo will prevent the connection from working.
Connect Your Account
In ValidEmailChecker, go to Integrations in the left sidebar and find Mailjet, or go to Bulk Upload and click Connect Email Platform. Enter an optional connection name (like "Marketing Mailjet" or "Client — Acme Corp"), paste your API Key and API Secret, and click Connect Account. We verify your credentials instantly and sync your contact lists.
Select a List and Configure
After connecting, click Sync Now to see all your Mailjet contact lists with subscriber counts. Select the list you want to verify, then choose your mode: Verify Only to review results before making changes, or Clean Automatically to remove invalid and disposable emails directly in Mailjet. You control exactly what happens to each email type — keep, unsubscribe, or delete.
Important: Delete permanently removes contacts from Mailjet with no undo. If you are unsure, use Unsubscribe instead — it keeps the contact but stops them from receiving emails. Start with "Verify Only" first.
Track Results in Real Time
Click Import Listand you will be redirected to the Uploads & Results page where you can watch progress in real time. No need to refresh — the page updates automatically. You can even close the browser — verification continues in the background. When complete, download results in CSV, XLSX, JSON, or TXT. If you chose automatic cleaning, changes are already applied to your Mailjet account.
Want a visual walkthrough with screenshots?
Our help center has the full step-by-step guide with images for every screen.
Two Ways to Verify
Verify Only
Import and verify your contacts without modifying anything in Mailjet. Your lists stay untouched — review results, download reports, and decide on your terms.
Best for:
Clean Automatically Recommended
Verify and clean in one step. Invalid emails get unsubscribed or deleted directly from your Mailjet account — no manual work required.
You control:
Delete vs Unsubscribe in Mailjet
Understanding the difference helps you choose the right cleaning action for each email type.
Unsubscribe
Marks the contact as unsubscribed in Mailjet. They remain in your account but will not receive any marketing or transactional emails.
Best for:
Delete
Permanently removes the contact from your Mailjet list. There is no undo — the contact and their data are gone from that list.
Best for:
Our Recommendation
Use Unsubscribe for Invalid emails (safer, preserves the record) and Delete for Disposable emails (fake or temporary addresses you do not want in your database). Keep Catch-all and Risky emails for manual review.
Tracking Your Verification Progress
Once verification starts, you are automatically redirected to the Uploads & Results page where everything updates in real time — no refreshing needed.
What you will see for each task:
Task ID
Unique identifier for this verification
List Name
Your Mailjet list name with icon
Upload Date
When verification started
Total Emails
Number of contacts being verified
Status
Processing, Completed, Failed, etc.
Progress
Percentage complete with progress bar
Estimated verification times:
100
Seconds
1,000
1–2 min
10,000
5–10 min
100,000
15–30 min
1,000,000
1–2 hours
Processing
Verification in progress
Completed
Click "View Results" to see breakdown
With Warning
Some emails could not be processed (credits refunded)
Failed
Something went wrong (rare)
Managing Your Mailjet Connection
Connection Actions
Click the three-dot menu next to any connection on your Integrations page:
Sync Now
Pull the latest contact lists from your Mailjet account.
Rename
Change the connection display name.
Delete
Remove this connection entirely. Does not affect Mailjet.
When to Sync:
Multiple Accounts
Managing email for multiple brands, clients, or departments? Connect them all.
Go to Bulk Upload → Connect Email Platform
Select Mailjet and see existing connections
Click "+ Add Another Account"
Enter the new API Key and Secret with a unique name
Name each connection clearly: "Marketing Team Mailjet," "Client — Acme Corp," "Transactional Emails."
Credits & Billing
1 Credit = 1 Email
Same rate as all other verification methods.
Unknown = Refunded
Credits returned instantly for unverifiable emails.
Duplicates = Free
Removed before charging — you only pay for unique emails.
Connecting = Free
Syncing your lists never uses credits.
Credits Running Low?
Before importing, you will see exactly how many credits the verification will use. If you do not have enough, purchase more credits instantly or set up auto-refill so you never run out during a critical verification.
15-Day Data Retention
Verification results are stored for 15 days so you can access and download them. After that, the data is automatically deleted. Your original contacts remain safely in Mailjet regardless.
Mailjet-Specific Tips
A few things unique to Mailjet that are worth knowing before you start verifying.
Two-Part Authentication
Mailjet is the only integration that requires both an API Key and an API Secret. This is similar to a username and password — the Key identifies your account, the Secret proves it is you. Both are required for every API request.
Tip: If you reset your Secret Key in Mailjet, the old one is invalidated. You will need to update the connection in ValidEmailChecker or delete and reconnect.
Transactional vs Marketing
Mailjet handles both transactional and marketing emails. Our integration works with both contact types — verify your marketing lists before campaigns and your transactional contacts to prevent bounce-related delivery issues.
Tip: Transactional contacts are especially important to verify — bounced order confirmations or password resets directly impact customer experience.
Secret Key Visibility
Mailjet only shows your Secret Key once when generated. ValidEmailChecker also never displays your full credentials after initial connection. If you lose your Secret Key or suspect it has been compromised, reset it in Mailjet and reconnect.
API Key Permissions
Make sure your API key has permissions to read contacts and lists. If you chose auto-cleaning, the key also needs write permissions to update contact statuses. Check your API key settings in Mailjet if cleaning actions are not being applied.
Troubleshooting
"Invalid API Credentials" Error
Double-check both your API Key and API Secret — you need both for Mailjet. Copy them fresh from Mailjet → API → API Key Management. Make sure you did not accidentally copy extra spaces. Check if your API key is still active and has not been deactivated in Mailjet.
"No Lists Found"
Your Mailjet account may not have any contact lists, or your API key may not have permission to view lists. Log in to Mailjet and verify you have at least one contact list with subscribers. Check your API key permissions and try creating a test list with a few contacts.
"Connection Failed"
This is usually a temporary issue — wait a moment and try again. Check if Mailjet is experiencing any service issues at status.mailjet.com. Try connecting from a different network if the issue persists.
Lists Not Updating After Sync
Mailjet's API cache can sometimes lag behind recent changes. Wait a few minutes and sync again. Check in Mailjet that the changes are actually saved. As a last resort, try disconnecting and reconnecting.
Clean Actions Not Applied
Your API key may lack write permissions — verify your key has full permissions in Mailjet. Mailjet may also be rate-limiting modifications on large lists. Check Mailjet's activity logs for errors and try cleaning a smaller batch first.
Some Emails Show "Unknown" Status
This happens when we cannot definitively verify an email — for example, the mail server did not respond or timed out. Credits for Unknown results are automatically refunded. You can re-verify these emails later.
Best Practices for Mailjet List Hygiene
Before Your First Verification
Ongoing List Hygiene
Recommended Actions
Frequently Asked Questions
Not at all. We only read your contact lists and — if you choose auto-cleaning — update contact statuses. Your email sending, campaigns, transactional emails, and automations continue normally. We never send emails through your Mailjet account.
No. Email verification happens entirely on our end. We check if addresses are valid without sending any emails to your contacts. They have no idea anything happened — the process is completely invisible to them.
Absolutely. Email lists decay over time — people change jobs, abandon accounts, providers shut down. Regular verification is actually recommended, especially for active marketing and transactional lists. We recommend quarterly verification at minimum.
Nothing. Safe emails are left completely alone. Only the email types you selected (invalid, disposable, etc.) are affected by your chosen actions. Your clean contacts are never touched.
We store verification results for 15 days so you can access and download them. After that, the data is automatically deleted. Your original contacts remain safely in Mailjet regardless of what happens in ValidEmailChecker.
The connection is removed from ValidEmailChecker, but your Mailjet account and contacts are completely unaffected. Past verification results remain accessible for 15 days. You can reconnect anytime with the same or different credentials.
Mailjet uses a two-part authentication system for security. The API Key is the public identifier, while the Secret Key is the private component. Both are required to authenticate API requests. This is similar to a username and password — one identifies you, the other proves it is you.
Yes. Both your API Key and Secret are encrypted and stored securely on our servers. We never display your full credentials after the initial connection. You can delete the connection at any time to revoke access from our side.
Yes. Connect as many Mailjet accounts as you need — one for each brand, client, or department. Give each a unique name (like "Marketing Team Mailjet" or "Client — Acme Corp") so you can tell them apart in the dashboard.
No. Connecting and syncing your account is completely free. You only use credits when you actually verify emails — 1 credit per email, same as every other verification method. Duplicates are removed before charging.
Ready to Clean Your Mailjet Lists?
Sign up, connect your Mailjet account, and verify your first list in under two minutes. 200 free credits included — no credit card required.
Get Started Free200 free credits · No credit card · Results in minutes