There is a time you get a bounce. What is it? It is the email you send but there is nobody to receive it. There are several stipulations about email bounces that help enlighten us about what is going on after you press the send button. This article will help you understand about email bounces, what are they and how to handle them.
There are two types of bounces. The first one is called “synchronous” and the other one is called “asynchronous”. They happen at different times. This is the reason why bounce information drops eventually after you sent your email campaign rather than showing up all at the same time.
Asynchronous Bounces – Work in the opposite way. Using the example above, inbox.com would receive your email and try to send it to its internal address records. Once it realizes that the email address is bad, mailbox.inbox.com will then send your mail server an email, letting you know.
Synchronous Bounces – This email bounces happen immediately during the email dialogue. For example, your sending server mail.acme.com connects to mailbox.inbox.com and tries to send an email to email@example.com. If mailbox.inbox.com is constructed for synchronous bouncing, it will instantly break off connection, and tell you that the address is bad.
Aside from the two types of email bounces, there are also two categories for it. Bounce meanings are marked via a chain of numeric codes. This is designed to help facilitate cross-language operability. These numeric codes that were used are standardized in two Request For Comment (RFC) documents. RFC is the recognized standard on the internet. There is the older RFC821 which has basic codes, and the updated RFC1893 which includes an enhanced set of codes.
Below are the two categories for email bounces:
Transient or “soft bounces” – This typically contains a leading “4” digit as part of the code. This bounces means that your messages are prohibited to be sent due to a short-term letdown but you can still retry to send your message later. An example of this bounces is due to a recipient’s inbox being full. The user is there and the email is still active but the recipient can’t just receive your message. An example would be: “421 Mailbox full”.
Permanent or “hard bounces” – these bounces are identified by a leading “5″ digit in the returned code. For example, a code such as “550″ in the older system or an enhanced “5.1.1″ codes both mean that the endpoint address is invalid, which signifies a permanent failure. Normally, these hard bounces are retried once or twice after a number of days, to justify for any errors on the receiving system. Example code: “5.1.1 Bad destination mailbox address”.
As with any standard on the Internet, this code system is not imposed by any sort of Internet police, so there are situations where systems are incorrectly or purposefully configured to return wrong or misleading codes. This is where bounce reasons come in. Bounce reason? What is it? A bounce reason is a message from the receiving system, such as “mailbox full”, that augments the bounce code. Sometimes you will see a bounce message such as “550 Mailbox is full”. The numeric code will signify that the mailbox was not found but the bounce message will say that the mailbox is just full. Even hard bounces needs to be tried at least once just to be safe and make sure that everything is working.
There’s always a chance that a good email address may be rejected due to these several discrepancies or it could be an invalid email address will remain active in your list. You should be capable of decreasing the possibility of the occurrences of these errors through good bounce handling technique.
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