When an email can't be delivered, it 'bounces', i.e. either your mail server or the recipients mail server responds with a message that says the mailbox is permanently unavailable (hard bounce), or there is some temporary situation, for example, the recipient mailbox is full that prevents delivery (soft bounce).
The Adestra known bounce system is an integral part of the platform which recognises and separates previously bounced email addresses, and automatically adds them to a mailing suppression list prior to sending a campaign. The email addresses in the mailing suppression list are not sent any campaign emails.
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Why it is important to manage bounces?
The large mail receivers (for example, Hotmail, Gmail, etc) use a complex sender reputation system that employs a number of different metrics, checking the bounce rate of the sender is one such metric. A high number of bounces generally means that the sender is not updating their mailing lists, and has a bad list management practices. This lowers the reputation and increases the chances of emails being blocked or junked. Furthermore, some receivers like Hotmail, take these old and abandoned email addresses which previously received emails but have been abandoned or closed for some time, and use them as a Spam Trap. Any campaigns sent to these spam traps can be penalised severely by spam filter systems.
By preventing the campaigns from reaching such email addresses, we increase the rate of deliverability. This protects the reputation of the campaign sender and proves their authenticity. Once an address is on the known bounce list, they cannot be sent to via Adestra.
What is a known bounce?
An email address is categorised as known bounce when there are three or more hard bounces from the email address over a period of at least 15 days, without a soft bounce or successful delivery in-between.
Note: If a successful delivery occurs between hard bounces, the 15 day time period is reset from the next bounce.
The system is in place across all clients to ensure good deliverability for everyone. So even if another one of our clients also has the same email address in their list, and it meets the known bounce criteria, the email addresses will not receive any campaigns, as it is known to have previously bounced.
Soft Bounce and Hard Bounce
The terms 'soft' and 'hard' bounces are used to categorise the different reasons why emails bounce. Our bounce report is split between these two kinds of bounce.
Hard Bounce
A hard bounce is an email message that has been 'returned to sender' because of an invalidity. The four hard bounces reported are:
- Invalid Domain: domain sent to is invalid, e.g. because of a typographical error (gnail.com instead of gmail.com).
- Invalid User: local part of address doesn't exist.
- Other Bounce: undetermined bounce.
- Over Quota: mailbox full.
Soft Bounce
Soft bounces are direct responses to your campaign, which could be automated. These fall under six categories:
- Inbox: a response directly to the email.
- Flame: a response which contains profanity.
- Blocked: receiving mail server flagged the email as spam.
- Out of Office: automatic Out of Office reply.
- Address Change: response notifying of address change.
- Temporary Notice: general temporary notice reply.
Note: Soft bounces are filtered by our system to ensure they are categorised correctly.
Reporting
Within the Campaign Report Summary you will see the 'Not Attempted' and 'Bounced' totals for your campaign.
Not Attempted
The 'Not Attempted' total is the number of recipients that Adestra did not send to, which includes email addresses that have previously bounced, and you can see the exact total of previously bounced using the 'detail...' link.
Bounced
The 'Bounced' total is the number of recipients who did not receive the attempted send. This means that Adestra has received an error message from the recipients' mail server to say that the email could not be delivered.
Inbound Report
There are a number of the reasons that may cause emails to bounce, which are broken down in the Inbound Report. Inbound messages are the emails that Adestra receives back in relation to your campaign.
Removing Bounces
If campaigns are bouncing it is good practice to either try and update the contact information or remove them from your contact lists. This will prevent them from being sent any further campaigns.
Removing bounced addresses from your lists is one of the most important things you can do to achieve good deliverability.
Note: This does not take the contact off the known bounce list.
Previously Bounced
Should a contact bounce three times over a period of 15 days, with no successful deliveries, Adestra will define them as 'Previously Bounced' and add them to an automatic suppression list. This means that campaigns will not be launched to these email addresses, meaning your deliverability shouldn't be affected. However, it will affect your reporting.
To see the total number of 'Previously Bounced' contacts you can go to a campaign summary report and by viewing the 'Not Attempted' statistic and clicking the 'detail...' link.
You can click on this total to view the contacts, and remove them from the list using the Data Viewer functions.
FAQ
Will my account be charged for sending to a previously bounced address?
No, Adestra will not attempt to send to previously bounced addresses, therefore you will not be charged.
What should I do if there is an address on the previously bounced list that shouldn't be there?
Although it is uncommon, if there is an address on the previously bounced list that you do not think should be there, contact Adestra Customer Support (adestra-support@uplandsoftware.com).
Can I bypass the known bounce system?
No, although if you think some addresses shouldn't be known bounces then we can test a sample of them for you to see.
Can addresses be removed from the previously bounced list and sent to again?
From time to time we're asked to remove addresses from our known bounce lists so they can be emailed again. This can be done in small quantities, however we would not recommend it. Although some of them will be delivered successfully, it is important to remember that the addresses are on the known bounce list because they have previously bounced three times over 16 at least days, so all of these addresses have been dead for a period of time.
Occasionally, email addresses may be reinstated. For example, or the domain may change hands, or the domain might have had no email for a while but now it does. However, it is worth bearing in mind that along with re-enabling a few potential false positives, you may also be emailing spam traps. Our tests have shown that although you may gain a few extra addresses for a large list, you will also lower your overall deliverability.