Types of bounces

When carrying out Email Marketing, some emails may not reach the target audience and bounce. Below we explain the different types of bounces that may occur.

1. Soft Bounce

These are temporary errors; in future campaigns it is possible that they will not appear as failures. MDirector eliminates and blocks them from the platform when they occur 3 times. That is, when the same softbounce occurs 3 times it is categorized as a hardbounce.

In this category we have:

• Protocol Error: the email was rejected due to STMP protocol messages or sequences of syntax errors (space between characters; “ñ”; a comma instead of dot.)

• Full Inbox (“Quota issues”): The destination email is temporarily disabled because the inbox is full. The email needs to wait 24 hours to enter. If after this time, it is still not allowed to enter, the client will no longer receive it.

• Bad Configuration: Message rejected due to configuration problems with the remote server.

• Bad Connection: Returned email because of bad a connection with the remote server.

• Content Related: Message that has been blocked or denied because the content of the email is not correct and could be considered spam: it has used $ or € symbols, or has words like “free”, include a flash…” etc. in the subject.

• Invalid Sender: It happens when the sender´s address does not have the correct format, or it can also occur when there´s a “Callback verification”, which is an anti-spam technique that verifies if an address, has been forged.

• Routing Errors: Emails with an existing domain but with an undefined mail service (does not have a declared MX registration).

2. Hard Bounce

These failures are constant, which means that you will never be able to receive the campaigns because: they do not exist, they are disabled. MDirector removes and blocks them from the platform as soon as they occur.

• E-mail Disabled: The email destination to which we sent the campaign, no longer exists.

• Non-existing E-mail: The email address we sent the campaign to, is no longer active.

• Bad Domain: A wrong email because the domain is incorrect (e.g. instead of writing Hotmail they have written homail). The tool will delete the email but keep the subscriber. In the menu Subscribers, it is possible to search for the contact and update it with the correct address.

• Bad-Mailbox: The message has been rejected because the email address is not valid or the user does not exist.

• Inactive Mailbox: It´s when the recipient´s mailbox is inactive. It is the notice that is given before the definitive cancellation of an address, and is susceptible to becoming a “Spam trap” (When an ISP retrieves an inactive address to check if the sender updates their database).

• Feedback Loop: the recipient considers and explicitly indicates that the campaign is a spam.

3. Bounces of type "Other types", or category "other".

With the category "other" nothing is done, it is passed over, they are softbounces and are not counted. Neither if they give 3 times bounces are marked or counted as hardbounce at any time. In Kibana (softbounce for us, internal error or an internal error for us).

(MDirector does not remove or block them from the platform)

• Spam Related: They are assigned to this category when the server filters determine that the submission is spam. The strictest filters are found in the corporate domains. One possibility is to ask the recipient in the email to add the sender's address to their address book.

• Message Expired: Emails that, after 72 hours of trying to be delivered, are returned are assigned to this category.

• Policy Related: Can be confused with "Spam related" errors, it also implies domain restrictions at the time of accepting emails by email clients, and therefore deals with security policies.

• Returned Email: This is the most complicated type of error to categorize. Emails with which there have been problems with the remote server, due to a bad connection with it. Each server can return the error with a message that is customizable.

• Relaying Issues: This happens when there´s no authorization from the destination server to allow the delivery (it could be from the IP or the sender address). It mostly affects only corporate domains.

• No answer from host: These occur when the destination server does not give an answer and delivery cannot be made.

• Virus related: These occur when the destination server considers that the email sent contains or could contain a virus, rejecting its reception.