Types of Bounces: tips to minimize them
Email bounces are a common situation faced by senders of email marketing campaigns. When an email cannot be delivered to the recipient, a bounce occurs. These bounces can be classified into two main categories:
Soft bounces:
A soft bounce occurs when an email is not delivered due to a temporary problem. For example, the recipient's mailbox may be full or the recipient's email server may be temporarily down. On the Icomm platform, up to 25 soft bounces are allowed per filled box before a contact is marked as bounced (hard). As long as a contact is accumulating fewer than 25 soft bounces, they are considered active and appear in the unseen contacts list.
Hard Rebounds:
On the other hand, a hard bounce occurs when an email cannot be delivered due to a permanent problem, such as an incorrect or non-existent email address. Once a contact reaches the limit of 25 soft bounces, it is considered to have transitioned to a hard bounce and is marked as a bounce. At this point, the contact is no longer considered part of the unseen contact list and will not receive future sends.
List of bounces:
Below is a list of the different types of bounces that can occur, along with their classification as soft or hard bounce:
Name | Type | Description |
|---|---|---|
Abuse | Soft Rebound | The email was reported as abuse |
Blocked | Soft Rebound | Blocked email account. |
Delivery not authorized, message refused | Soft Rebound | The sender is not authorized to send to the recipient in question. This may be a result of filters on the host or sender. |
Delivery time expired | Soft Rebound | The delivery time has expired according to the sending configuration without the possibility of delivering the message. |
Directory server failure | Soft Rebound | The network system was not able to send the message, because the directory server was unavailable. |
Disposable Account | Hard Rebound | The email account is from a disposable account provider and is not valid for email marketing |
Exclusive Subdomain Use | Hard Rebound | The subdomain is used by the provider for specific communication from their system and should not be used to send |
expired | Soft Rebound | Expired email account. |
failed | Soft Rebound | Unidentified General Error |
invalid | Soft Rebound | Syntactically invalid email account |
Free Account Domain Error | Hard Rebound | The account has a domain similar to those of free email providers, however it is not correct |
Generic Organization Account | Hard Rebound | This account is probably related to a specific department in an organization, and not to a person |
inexistant | Hard Rebound | Non-existent email account. |
Inexistant Bad destination mailbox address | Hard Rebound | The mailbox detailed in the address does not exist. |
Inexistant Bad destination mailbox address syntax | Hard Rebound | The detailed mailbox contains syntax errors. |
Inexistant Bad destination system address | Hard Rebound | The destination server specified in the mail account does not exist or is unable to accept mail. For email account, this means the right part that follows the @ in the address. |
Inexistant Bad senders mailbox address syntax | Hard Rebound | The mailbox is syntactically invalid. This can apply to any field in it. |
Inexistant Bad senders system address | Hard Rebound | Non-existent email account |
Inexistant Domain Name Not Found | Hard Rebound | DNS error: domain name not found. |
Invalid command | Soft Rebound | A send transaction command was issued that is not supported by the destination server. |
junkmail | Soft Rebound | The email has been marked as Spam (obsolete method for transports like Hotmail, Yahoo, Aol) |
Mail system full | Soft Rebound | The storage of the destination email account has been exceeded. |
Mailbox disabled, not accepting messages | Soft Rebound | The account exists, but is not accepting messages. This can be a permanent error for the account if it is not re-enabled, or a temporary error if it was disabled for a time. |
Mailbox full | Soft Rebound | The mailbox is full because the user has exceeded the administrative quota limit or mailbox capacity. |
Mailing list expansion problem | Soft Rebound | The recipient is a mailing list whose policies do not allow additional members without prior authorization from the administrator. |
Media not supported | Soft Rebound | Something in the content of the message caused it to be considered undeliverable. |
Message length exceeds administrative limit | Soft Rebound | The message length limit imposed by the mailbox has been exceeded. |
No answer from host | Soft Rebound | There was no response to the outgoing connection attempt, because the remote system was busy, or was not able to accept the call. |
Other address status | Soft Rebound | Something about the address detailed in the message is causing this DSN. In general, they refer to syntax errors that are not supported by the destination server. |
Other or undefined mail system status | Soft Rebound | The destination server exists and normally receives mail, but some unidentified reason caused this temporary bounce. |
Other or undefined mailbox status | Soft Rebound | The mailbox exists, but something in the destination box caused the bounce. |
Other or undefined media error | Soft Rebound | Something in the content of the message caused it to be considered undeliverable and the reason cannot be correctly expressed by the detailed codes. |
Other or undefined network or routing status | Soft Rebound | A connection could not be established with the destination server but the reason for rejection cannot be expressed correctly with the defined codes. |
Other or undefined protocol status | Soft Rebound | A problem has occurred with the protocol necessary to send the message to the next hop and the problem cannot be correctly expressed by the codes provided. |
Other or undefined security status | Soft Rebound | The message has been bounced for security reasons on the destination server and the problem cannot be correctly expressed by the codes provided. |
Other undefined Status | Soft Rebound | Other Undefined Status is the only undefined error code. It is used to categorize the reasons for bounces that cannot be identified because they are not cataloged by the destination server. |
overquota | Soft Rebound | Email account without space. |
Presumed invalid account | Hard Rebound | An invalid account is presumed |
Rejected By Google Groups | Soft Rebound | Message rejected by google groups. |
Risky Email | Hard Rebound | The destination email account exists but there are factors that indicate that it could bounce or be of low quality. |
Role Account | Hard Rebound | Role Account (do not use in marketing shipments) |
Routing loop detected | Soft Rebound | The message could not be delivered because recursion was detected in the routing route to the recipient's mail server. |
Syntax error | Soft Rebound | A send transaction command has been issued whose syntax is not valid according to the destination server. |
System incorrectly configured | Soft Rebound | The server is not configured to allow entry of this type of message. |
System not accepting network messages | Soft Rebound | The server where the mailbox resides is not accepting messages. |
System not accepting network messages (Spam Related) | Soft Rebound | The server where the mailbox resides is not accepting messages because it considers the content as unwanted. |
System not capable of selected features | Soft Rebound | Some specific features in the message are not supported by the destination server. This can occur at the gateway when certain features of a message are not being supported. |
TimeOut | Soft Rebound | Shipping time expired. |
Unable to route | Soft Rebound | The message could not be delivered due to problems in routing to the destination server. |
Tips to minimize bounces:
- Maintain an updated and clean subscriber list: Periodically remove invalid, outdated or inactive email addresses from your subscriber list.
- Use authentication and verification techniques: Implement authentication methods, such as email subscription confirmation, to ensure that subscribers are real and interested in receiving your communications.
- Monitor and analyze bounces: Track bounces and analyze the reasons behind them. This will help you identify patterns and take corrective action.
- Segment and personalize your campaigns: Sending relevant and personalized content to your subscribers can increase the
engagement and reduce the likelihood of your emails being marked as spam or bounced.
- Use email verification tools: There are tools and services that can help you verify the validity of email addresses before adding them to your subscriber list.
- Educate your subscribers: Provide clear information on how to update their subscription preferences or unsubscribe if they no longer wish to receive communications from you.
Updated on: 04/29/2024
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