A contact’s email address can be suppressed for many different reasons. Suppressions can happen intentionally or unintentionally. Each suppression is labelled with a reason, which gives you some further information about what caused that particular email address to be suppressed.
This article covers suppression reasons for email addresses. Learn more about mobile number suppressions and contact-level suppressions in SMS contact opt-outs and Understand contact and channel suppressions.
Email suppression reasons
Suppression reason | Details |
Soft bounced | The contact's email address is temporarily unreachable:
A soft bounce email suppression happens once an email address reaches the soft bounce limit that's set for your account. |
Hard bounced | The contact's email address is permanently unreachable:
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Unsubscribed | The contact is unsubscribed from your email campaigns:
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Suppressed by you | Someone in your account added this email address to the suppression list by hand, either you or a managed user. It isn't something the contact did, and it isn't caused by a bounce or a complaint. Think of it as a Do not contact flag you control, and you can remove it at any time.
If you have chosen to sync opt-ins through the Dotdigital Marketing NetSuite integration, contacts who have not opted in are added to the suppression list with the reason Suppressed by you. |
ISP complaint | The contact marked your email campaign as spam. |
Mail block | The contact's email provider doesn't want to process email campaigns from you, likely because of the attachments in your campaigns. |
Direct complaint | The contact made a direct complaint to Dotdigital, and we suppressed this contact’ email address from your account. |
Globally suppressed | Contacts who've either complained directly to us in the past or are email addresses which are known spam traps or invalid addresses. |
Domain suppression | Contacts whose email domain you have previously added to your suppression list. |
Reverse a suppression
Whether you can bring an email address back depends on why it was suppressed.
Resubscribed immediately, with no confirmation email
Suppressed by you
Resubscribed only after the contact confirms
Unsubscribed
Soft bounced
Hard bounced
When you resubscribe one of these, we send the contact a resubscribe confirmation email. The email address stays on the suppression list until the contact selects the link in that email.
Can't be resubscribed by you
ISP complaint
Globally suppressed
Domain suppression
For any reason not listed here, and for the full resubscribe steps, learn more in Resubscribe a contact.
The contact never received the resubscribe confirmation email
Until the contact confirms, their email address stays suppressed, so a confirmation email that doesn't arrive leaves the resubscription unfinished. Work through the following:
Ask the contact to check their spam, junk, and Promotions folders, and to search their inbox for resubscribe.
Check whether another resubscribe email was sent to the same contact in the last hour. You can only send one resubscribe email per contact per hour, and an attempt made inside that hour sends nothing.
Check how long ago the email was sent. A resubscribe confirmation link is valid for 30 days. If the contact doesn't confirm within 30 days, the pending opt-in expires and the link stops working.
If the contact's organisation filters inbound mail, ask them to check with their IT team whether the message is held or quarantined.
To send a new confirmation email, resubscribe the contact again from Audience > Suppressions.
If the contact still doesn't receive it, contact Dotdigital Support. We can check whether the message was accepted by the recipient's mail server.
Learn more about the content of this email in Customise the resubscribe confirmation email.
Suppressed, unsubscribed, and deleted contacts
Unsubscribe from account and Suppress from account both stop you sending to a contact, and both add the contact to the suppression list. The difference is who decided, and what it takes to undo:
Unsubscribe from account records that the contact opted out. The suppression reason is Unsubscribed. To email them again, the contact has to confirm the resubscription themselves.
Suppress from account records your own decision not to contact them. The suppression reason is Suppressed by you. You can reverse it yourself, immediately.
Deleting a contact is different again: it removes their record rather than stopping your sends. Deleting a contact doesn't unsubscribe them, so a deleted contact who's later added back can receive campaigns again.
In Marketing, you can choose to manually suppress an email address from your account.
When you suppress a contact's email address, it's added to the account suppression list with the reason Suppressed by you, and they no longer receive any email communications from your account. You can think of suppression as a Do not contact status, which you can apply to a contact's email address, mobile number, or both.
Suppressing a contact can only be done by you or a member of your team; contacts can't suppress themselves.
Contacts marked as unsubscribed can only be resubscribed or exported, they can't be converted into suppressed status.
Unsubscribed email addresses
Contacts whose email address is unsubscribed have decided they no longer want to receive your email communications. Their email address is added to the account suppression list with the suppression reason Unsubscribed.
Contacts can also unsubscribe from individual marketing preferences or lists, rather than unsubscribing from all communications from you.
What a suppression doesn't stop
Suppression and unsubscribes apply to your marketing communications. They don't apply to transactional messages, which are sent in response to something the contact did rather than as marketing.
Product notifications
Back in stock notifications are transactional. A customer who signs up for one hasn't necessarily consented to your marketing, and unsubscribing from your marketing doesn't unsubscribe them from a product notification. These customers also don't appear in your lists or segments unless they've separately signed up to your marketing, or been added to your account another way, such as a sync from your ecommerce system after an order.
Learn more in Product notification reports.
Transactional email
Transactional email is sent to individual contacts based on their interactions with you, and isn't subscription-based. Transactional emails don't carry the List-Unsubscribe header for the same reason.
Learn more in Understand List-Unsubscribe.
Hard and soft bounces
A hard bounce happens when an email is sent to contacts whose addresses are permanently unreachable, most likely because they, or the server they were hosted on, don't exist: the email address is invalid. A hard bounce immediately results in the email address being placed on the suppression list.
A soft bounce happens when an email is sent to contacts whose addresses are temporarily unreachable, possibly because their mailboxes are full or their mail servers are having temporary issues accepting email. It doesn't necessarily mean the email address is invalid.
Suppression
If an email address hard bounces once, or soft bounces too many times, it is suppressed from your account to prevent you from sending to it. This helps to protect your sending address and server from being blocked for spamming.
You can set how many times an email address can consecutively soft bounce before it becomes suppressed in your account. Using lower thresholds ensures quick suppression of repeatedly bouncing email addresses, reducing the risk of sender reputation damage. However, higher thresholds can prevent suppression of valid addresses suffering temporary issues.
Types of bounce response
You might sometimes see a bounce response for an email address with some additional information about the type of bounce:
Soft bounce - DNS failure: Although we tried several times, we were unable to determine which mail server is configured to accept mail for this email address. This may be due to the correct mail server undergoing maintenance at the times we attempted to send the message.
Soft bounce - mailbox full: The recipient's mailbox is too full to accept the email you tried to send them.
Soft bounce - message too large: The recipient's mail server won't accept a message of this size.
Bounce - no email address: A bounce came back, but the mail server we sent the message to didn't indicate who the bounce was on behalf of. We've identified the intended recipient, based on the content of the message being returned.
General bounce: The mail server returned the message to us, but didn't indicate a reason why.
A sudden increase in bounces at one email provider
If bounces spike across many addresses at the same provider, such as Yahoo, AOL, or Sky, over a few days, the cause is usually on the provider's side rather than in your data. Providers throttle or reject mail based on your sending reputation, your authentication records, and your spam complaint rate, and they apply those decisions across every address they host.
A spike of this shape isn't a suppression problem, and suppressing the affected addresses doesn't resolve it. Before you contact us, check:
Your sender reputation.
Whether the bounces are soft or hard, in the bounce drilldown report for the campaign.
Whether the spike began alongside a change to your sending domain, your from address, or your sending volume.
If the pattern continues, contact Dotdigital Support with the affected campaign name and some example addresses. We can look up the rejection your recipients' servers returned, which tells us whether the block is reputation-based, authentication-based, or a policy applied by that provider.
See a bounce for a contact you can't find
You might receive a delivery failure for an email address that you can't find in any list, and that isn't in your suppressed contacts either. A few things cause this.
The email address is globally suppressed
Email addresses on the Global Suppression List (GSL) are held outside your account, so the contact's record no longer appears in your lists or in your suppressions.
The email was transactional
Transactional email can be sent to any email address, whether or not it's a contact in your account. Transactional sends appear in the Transactional email dashboard rather than against a contact. Go to Analytics > Dashboards, expand More dashboards, then select Transactional email.
The email was a product notification
Customers signed up to a back in stock notification don't appear in your lists or segments unless they've also signed up to your marketing. To see who a notification went to, go to Analytics > Reports, expand More reports, then select Product notifications.
The contact was deleted but the send had already begun
Deleting a contact doesn't unsubscribe them. Deleted contacts are held in the Recycle bin for 30 days, and a contact added back to your account during that time can receive campaigns again.
The bounce didn't name a recipient
A bounce with the response Bounce - no email address came back without the receiving server saying who it was for. We identify the intended recipient from the content of the returned message, so the address in the bounce isn't always one you hold.
To check which addresses a specific campaign bounced on, go to Analytics > Reports, select the campaign name, then expand More reports and select the hard bounces or soft bounces drilldown report.
View the suppression reason for an email address
You can view the suppression reason for an email address in the suppressed contacts table:
Go to Audience > Suppressions.
Locate the Email status column.
You can also view the email status in the Single customer view:
Go to Audience > Suppressions.
Use the search field or filter to find the contact, then select their email address to open the Single customer view.
Select the Data fields tab at the top of the page.
You can see the email status next to the Email field.
Email reports
To view bounced emails, unsubscribes or ISP complaints for a specific email campaign:
Go to Analytics > Reports.
Select the email campaign name.
Expand the More reports drop-down menu and select the relevant drilldown report.
Automatic unsuppressions
If an email address on the Global Suppression List (GSL) engages with any email campaign:
We remove the contact from the GSL if they were added because they hard bounced, soft bounced, or had no MX record.
The contact’s global soft bounce count resets to zero.
Additionally, email addresses are removed from your account’s suppression list after a year if they were suppressed because they reached your soft bounce threshold.
When email addresses are unsuppressed for any of these reasons, they aren't automatically added to your account - but they can be created or uploaded again.
Manage suppressed contacts from list imports
If specific contacts are flagged as suppressed during a contact list import, you can view and export them for further review. Follow the steps below to complete this process:
Select the Account menu icon and go to Settings > Contacts > Import History.
Locate the specific import and click Report on the right-hand side.
On the report page, review the number Contacts not imported listed on the right.
Export the suppressed contacts as a CSV file for further investigation or record-keeping purposes.
This process ensures you can identify and manage contacts that were not imported due to suppression.