3 Factors that Impact Your IP Reputation

ISPs base their decision about whether incoming emails will be placed in the inbox (rather than the spam folder) largely on the sender’s IP reputation. Every email you send travels through an IP address. Every IP address has a reputation score that is between 0 and 100. This reputation score changes over time based on the quality of the emails that are sent.

How is your IP reputation score calculated?

There are 3 major factors that lower the IP reputation score and it’s important to be familiar with them:

1. Complaints:

Flagging an email as spam is a direct complaint by the recipient.  The recipient can flag any email with a simple click thanks to the …mark as spam“ button present in most electronic messaging interfaces.

The number of spam complaints has a very high impact on the IP reputation score. To avoid any negative impact on your deliverability, we advise you to keep your spam rate under 0.1%.

As a reminder, the basic rule, of course, is to stop sending email to an address that marked you as spam! One of the added values of Mailjet is to manage this automatically: we retrieve this information for you from all the ISPs who provide …feedback loops.“

For more details about how to manage spam complaints, please refer to our documentation page about various email statuses.

2. Errors/incorrect addresses (soft and hard bounces):

There are several types of errors, also known as hard and soft bounces. An inbox that is full or temporarily unavailable leads to a …soft bounce“.  This error is temporary so you may resend the email as necessary (and don’t worry, Mailjet manages all of this for you!). These types of bounces, though temporary, are problematic.

On the other hand, if the email address is spelt incorrectly or does not exist, this is considered a hard bounce and it may indicate that the sender is not keeping their contact lists cleaned and up-to-date. And in some extreme cases, senders may be generating addresses at random!  As a result, sending emails to non-existent addresses negatively affects your IP reputation.

3. Spam traps:

Also called honeypots, these email addresses are made to trap spammers. They may have been purposely created or may be old addresses turned into Spam Traps.

The administrators of these traps are 100% certain that no opt-in has ever been confirmed. So they know that every email received has not respected best emailing practices (nor most laws).

Purchased or rented lists systematically contain a great number of these spam trap email addresses, which is why Mailjet prohibits you from using 3rd party lists. Someone who sends to a spam trap has no excuse! As a result, sanctions are often very severe (blacklisting, etc.).

Wrapping up

The health of your email list is extremely important to maintain a good deliverability. At Mailjet, we use different methods to monitor your IP reputation to ensure your emails are reaching the inbox. If you want to learn more, check out our Email Deliverability Guide!