THE ZB GUARANTEE
Other companies say it, we put it in writing. ZeroBounce, the leader in email validation, makes you the promise of cleaner and safer email lists. We guarantee the following accuracy rates at a minimum:
- 96%+ Accuracy rates on AOL, Yahoo, and office 365 email accounts. This does not include disabled accounts.
- 99% Accuracy rates on everything else.
How the Guarantee works:
If the accuracy rates are below these thresholds, we will refund 5 times the amount for each 1%. Let's say you have a 97% accuracy rate, which is 1% below the guaranteed threshold of (99% Accuracy rates on everything else). We will refund 5 x 1% (or 5%) of your total validation cost for those emails. If your accuracy rate is 2% below the guaranteed threshold, our refund will be of 10% of your costs. If it's 4% below, the refund will be 20%, and so on.
In order to qualify for the guarantee, the following conditions must be met:
- You only email the _valid.csv and remove all toxic and disposable emails.
- You email the list within 72 hours after cleaning.
- Bounces must be invalid emails (Hard Bounces).
- Bounces due to spam content, blacklisted IP's, technical Issues, invalid mail configuration, throttling, etc do not qualify for the guarantee.
- The minimum list size must be 1000 emails.
- This list must be an opt-in list that you collected and not purchased from a 3rd party
- You must provide an export of your full mailing of all emails you sent to and their bounce responses (the actual SMTP Codes and messages of the bounces), not your email sender classifying it as a bounce. ZeroBounce does not guarantee the acceptance of your cleaned list at any ESP provider.
SMTP BOUNCE CODES
SMTP Bounce codes are returned by the different mail servers indicating why they didn't accept the emails that you sent it. It can be for many different reasons, having an email bounce is not always an indicator of an email being invalid. It can be for many other reasons, the most common is that the spam filters identified the message as "Spam Content" and rejected it.
In order to determine why the emails that were sent bounced, it's important to have access to these codes, so you can make adjustments and decisions to remedy the issue.
Below you will find a summary of codes, keep in mind, there are thousands more, depending on the mail server the same codes will have different meanings, these are just a few examples.
5.X BOUNCE CODES (PERMANENT FAILURES)
Address does not exist
Other address status
Bad destination mailbox address
Bad destination system address
Bad destination mailbox address syntax
Destination mailbox address ambiguous
Destination mailbox address valid
Mailbox has moved
Bad sender’s mailbox address syntax
Bad sender’s system address
Other or undefined mailbox status
Mailbox disabled, not accepting messages
Message length exceeds administrative limit.
Mailing list expansion problem
Other or undefined mail system status
Mail system full
System not accepting network messages
System not capable of selected features
Message too big for system
Other or undefined network or routing status
No answer from host - the address is invalid
Routing server failure
Unable to route
Routing loop detected
Delivery time expired
Other or undefined protocol status
Too many recipients
Invalid command arguments
Wrong protocol version
Other or undefined media error
Media not supported
Conversion required and prohibited
Conversion required but not supported
Conversion with loss performed
Other or undefined security status
Delivery not authorized, message refused
Mailing list expansion prohibited
Security conversion required but not possible
Security features not supported
Cryptographic algorithm not supported
Message integrity failure
4.X BOUNCE CODES (TEMPORARY FAILURES)
service not available, closing transmission channel
Requested mail action not taken: mailbox unavailable (e.g., mailbox busy)
Requested action aborted: error in processing
Requested action not taken: insufficient system storage