8 tips for great email reputation and maximum deliverability – Part IV


7. Bounce management

There are a lot of reasons why emails may bounce. In most cases, it is the result of people abandoning their email accounts, changing jobs or configuration issues. On the other hand, bounces as a result of invalid email addresses can be minimized or avoided altogether. Bounces are essentially email messages that cannot be delivered for one reason or another. We distinguish two types of bounces:

  • Soft bounce: the email message can temporarily not be delivered. This happens e.g. when a user's mailbox is full.
  • Hard bounce: the email message can permanently not be delivered. This is the case for misspelled email addresses for instance.

Bounces should be monitored and cannot be ignored, as improper bounce management can result in a decrease of reputation, endangering the deliverability of future campaigns. Also, the risk of hitting spam traps increases significantly.

But how do I reduce my bounce rate? Maintaining a good list hygiene is the easiest way to ensure that bounces are kept to a minimum. In most cases, this can be achieved in your email marketing tool. In the Selligent Manager, you can activate "Email Quality" and configure the level of strictness as shown in the picture below.

Bounce management

However, it also pays off to manually check for typos and incorrectly formatted email addresses from time to time, especially when importing addresses and sending to a list for the first time. Good opt-in and opt-out management, as described in the previous chapters, also assists in list maintenance. Using a confirmed opt-in process, for example, ensures that each address is validated by the subscriber before it can be added to your list.

8. Maintain permissions over time

When someone gives you permission to communicate with them, the clock starts ticking. If you defer from communicating with them right away, you run the risk of permission expiration (and eventually spam complaints). People usually forget that they subscribed for a newsletter or email campaign after six months.

Therefore, it is a good idea to communicate with your subscribers on a semi-regular basis. As with all marketing efforts, balancing the frequency of your messages is extremely important. Most sources indicate that either a bi-weekly or monthly sending schedule produces the best results. This may vary, however, based on your type of newsletter and subscribers that you have.

It is also important to note that Internet service providers (ISPs) and email service providers (ESPs) are increasingly looking for ways to stop spam by using filtering, black lists and white lists. A much used practice is the so called spam trap. This is essentially an email address designed to receive spam and trap mailers that spam or use questionable mailing practices.

Spam traps come in three flavors

  • Recycled email addresses: typically an ISP will deactivate an abandoned email address. The email address will return an unknown bounce code. At some point however, the ISP will recycle the address, reactivate it, convert it into a spam trap and allow email to be received again by the email address.
  • True spam traps: these are email addresses especially conceived to capture spammers. These addresses will never subscribe to receive emails. Many spam trap operators will post these email addresses on websites, forums, etc. Malicious people will harvest these email addresses to be mailed to and sell or trade them.
  • Unknown users: this is a type of hard bounce that indicates that an address is invalid, expired or abandoned by the user. After a certain period of time (usually 6 - 12 months), the ISP will recycle these email addresses into a spam trap and stop sending 'unknown user' error codes. These kinds of email addresses are taken up a lot in sellable email lists.

Sending emails to a spam trap address can quickly damage your deliverability reputation and cause you to be blocked or get you blacklisted. Fortunately, they can be avoided by following some simple rules:

  • Only use permission-based email sending.
  • Never purchase third party email lists, as they often contain spam trap addresses.
  • Set up a proper bounce handling process for hard and soft bounces. Also, never reactivate bounced subscribers.
  • Send on a regular basis.

Next to that, you might want your subscribers to re-subscribe if they have not responded to an email during the last six months. You could do this by asking them if they still want to continue to receive your messages and register their response. After all, inactive users have a negative effect on your statistics and your sending speed. Their email address can also be easily converted into spam traps and add additional risks to your mailings.

Besides, as these subscribers have been inactive for a considerate amount of time, is it worth your while putting a lot of marketing effort into it? Chances are small that they will start to generate revenue all of a sudden. It is also beneficial to allow subscribers to manage their preferences (e.g. via a profile page). In this way, people can choose the content and the frequency of the emails they want to receive. By giving subscribers control, you reduce the chance of spam complaints.

Finally, you should remind people that they subscribed. This can easily be done by including a standard message in the header or footer of each email you send. A short note in the header - like "Thank you for subscribing to our newsletter. Here is our latest issue:" - can make a big difference: you remind your subscribers that you are not sending unsolicited content.


Missed the first 6 tips? Go to:

Or download our Guidelines "Designing and sending emails" for the full content.



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