Soft Failures — Block

Block failures indicate email addresses were intentionally refused by receiving mailbox providers. A block can occur when the receiving server refuses the connection, refuses to accept the email during the connection, or returns the email undelivered after several delivery attempts.

Note: This may be the result of other mailings sent from other clients and not directly related to the one you sent. However, if you see these types of failures, please note the best practices outlined in this section to minimize them in future mailings.

Possible causes

Blocks occur for multiple reasons, including the receiving system's use of a blacklist or other filter, as well as the spam complaint rate or bounce rates for specific bounce codes. The specific failure reasons can help determine the likely causes.

Suggested actions

  • If the block is from one of the major mailbox providers, our team of email specialists will work to take the appropriate corrective action and seek to have the block removed. No action is required by you.

  • When the block is placed by a secondary or lesser known provider, consider the percentage of emails you are sending to it and contact us if additional action is necessary.

The email was blocked because of recipient complaints that E-mails sent through the IP address are SPAM. This may be the result of other mailings sent from other clients and not directly related to the one you sent.

Possible cause: Low engagement

Recipients may not be engaged with your organization (no/low opens or clicks). Inactivity directly correlates to complaints.

Suggested actions

  • Conduct separate reactivation mailings to inactive recipients. Purge those who don't respond from your list.

  • Identify inactive customers from regular mailing programs who have not opened or clicked in the past six months.

  • Send those customers a separate email reminding them of the relationship and allow them to opt out if they no longer wish to continue the email relationship.

  • Provide opportunities in subsequent regular mailings for 30 more days to re-engage.

  • For those who did NOT opt-out and those with activity in the subsequent campaigns continue normal mailings.

  • Permanently remove those recipients who have not clicked anything during this window, and send a final “we are sorry to see you go” email that gives them a last chance to opt back in to the mailing program.

Possible cause: High/low frequency

Recipients may be associating your email with SPAM if you’re mailing too frequently or not frequently enough to prompt recall of permission to send to the address.

Suggested actions

  • Review your email sending cadence and reset it consistent with recipient expectations.

  • Ensure that the recipient understands what they are signing up to receive, including the frequency (possibly the day and time) of when they can expect to receive the email.

  • Offer choice to recipients on both frequency and content.

Possible cause: Poor relevance

Recipients may associate your email with SPAM if they're not targeted appropriately or if the content is not relevant to their preferences.

Suggested actions

  • Tighten your targeting criteria and associate your content with preferences. Develop feedback mechanisms to confirm relevance.

  • Provide the recipient with sample emails or newsletters that they can review during the sign-up process.

  • Allow recipients to update their profile with additional information so you can increase the relevance of the content you send them.

Possible cause: Weak branding

 

Recipients may not realize that the email is from you if your branding is weak.

Suggested action

Use consistent, prominent branding in your From Address, From Name, and Subject Line.

Possible cause: Weak permission

Recipients may not associate your email with permission granted to you or a third party, such as a list rental or affiliate program.

Suggested actions

  • Use more explicit methods to obtain and disclose permission such as using double opt-in.

  • Investigate permission practices of affiliates.

  • Send follow-up messages to confirm consent before incorporating addresses you obtain from third parties into your list.

  • Provide permission statements to remind recipients why they’re getting your email in prominent locations on all messages you send. For example, you may want to provide a sentence or two describing how they subscribed to your mailing list.

  • Reconfirm permission and track other indicators of sustained interest, such as clicks on links, donations, etc.

Possible cause: Inadequate complaint management

Recipients who have opted to not receive mailings from one mailing are included as receivers in another similar one.  

Suggested action

  • Build email campaigns and newsletters with related topics and content to help recipients identify which they would like to receive.

  • Build the proper email or newsletter template structure to ensure opt-out processes for specific mailings are handled according to the correct hierarchy.

The email was blocked because the domain name or IP address is on an external blacklist.

Possible cause: High spam complaints

Your email may be generating a high rate of spam complaints. See “Block/Spam Complaint” for likely causes.

Suggested action

See “Block/Spam Complaint” for suggested actions.

Possible cause: Spam trap hits

Your email may have been caught in spam traps used to identify spammers.

Suggested actions

  • Know your data sources and keep your organization’s list management practices updated and active. Investigate the compilation and management practices of any third parties you use.

  • Confirm consent before incorporating email addresses you obtain from third parties into your list.

  • Clean your list as part of your normal email management practices. While we automatically place all email addresses which hard fail on the blacklist so they are suppressed from future mailings, we expect you to also actively manage and update your list.

Possible cause: Inadequate complaint management

Recipients who have opted to not receive mailings from one mailing are included in the receiver base for another similar one.

Suggested actions

  • Build email mailings and newsletters with related topics and content to help recipients identify which they would like to receive.

  • Build the proper email or newsletter template structure to ensure opt-out processes for specific mailings are handled according to the correct hierarchy.

The email was blocked because your domain name or IP address is on a mailbox provider's internal blacklist.

Possible cause: High spam complaints

Your email may be generating a high rate of spam complaints. See “Block/Spam Complaint” for likely causes.

Suggested action

See “Block/Spam Complaint” for suggested actions.

Possible cause: Poor list management

Your email may be generating high failure rates that are associated with SPAM or poor list management practices. See “Block/List Management” for likely causes.

Suggested action

See “Block/List Management” for suggested actions.

The email was blocked because some aspect of the content triggered a SPAM filter. There are hundreds of SPAM filters. Most have no significant impact on your deliverability. Others may have broader impact depending on whether the mailbox providers you send to use them.

Possible causes

The email may have triggered a SPAM filter due to:

  • Prohibited words or phrases

  • Too many HTML tags

  • Too many images

  • Too many different font styles, sizes, or colors

Suggested action: Content review

Send the content through a SPAM score tool such as SpamAssassin. Based on the score, adjust your templates, language, style, and HTML as much as possible without sacrificing the effectiveness of your message.  

Note: Mailbox providers rely less on content blocks than they did in the past. Now, they typically rely more heavily on factors such as engagement and authentication.

The email was blocked because one or more of the URLs in the email is associated with SPAM complaints. This may be the result of other mailings sent from other clients and not directly related to the one you sent.

Possible cause: Poor URL usage

URLs are being used too broadly. The practices of affiliates or others may be impacting your reputation.

Suggested actions

  • Segregate your URLs. Use distinct URLs for each class of mail, such as transactional or newsletter.

  • Verify the URL is not used in other email that might be perceived as SPAM, such as from other divisions or affiliates or your organization. Investigate underlying cause of problem URLs.

Possible cause: Low engagement

Recipients may not be engaged with you (no/low opens or clicks). Inactivity directly correlates to complaints.

Suggested actions

  • Conduct separate reactivation mailings to inactive recipients. Purge those who don't respond from your list.

  • Identify inactive recipients from regular mailing programs who have not opened or clicked in the past six months.

  • Send those customers a separate email reminding them of the relationship allowing them to opt out if they no longer wish to continue the email relationship.

  • Provide opportunities in subsequent regular mailing for 30 more days to re-engage.

  • For those who did NOT opt-out and those with activity in the subsequent campaigns continue normal mailings.

  • Permanently remove those recipients who have not clicked anything during this window, and send a final “we are sorry to see you go” email that gives them a last chance to opt back in to the mailing program.

Possible cause: High/low rrequency

Recipients may be associating your E-mail with spam if you’re mailing too frequently or not frequently enough to prompt recall of permission to send to the address.

Suggested actions

  • Review your E-mail sending cadence and reset it consistent with customer expectations.

  • Ensure that the recipient understands what they are signing up to receive including the frequency (possibly the day and time) of when they can expect to receive the E-mail.

  • Offer choice to recipients on both frequency and content.

Possible cause: Poor relevance

Recipients may associate your email with SPAM if they're not targeted appropriately or if the content is not relevant to their preferences.

Suggested actions

  • Tighten your targeting criteria and associate your content with preferences. Develop feedback mechanisms to confirm relevance.

  • Provide the recipient with sample emails or newsletters that they can review during the sign-up process.

  • Allow recipients to update their profile with additional information so you can increase the relevance of the content you send them.

Possible cause: Weak branding

Recipients may not realize that the mail is from you if your branding is weak.

Suggested action

Use consistent, prominent branding in your From Address, From Name, and Subject Line.

Possible cause: Weak permission

Recipients may not associate your email with permission granted to you or a third party, such as a list rental or affiliate program.

Suggested actions

  • Use more explicit methods to obtain and disclose permission such as using double opt-in.

  • Investigate permission practices of affiliates.

  • Send follow-up messages to confirm consent before incorporating addresses you obtain from third parties into your list.

  • Provide permission statements to remind recipients why they’re getting your email in prominent locations on all messages you send. For example, you may want to provide a sentence or two describing how they subscribed to your mailing list.

  • Reconfirm permission and track other indicators of sustained interest, such as clicks on links, donations, etc.

Possible cause: Inadequate complaint management

Recipients who have opted to not receive mailings from one mailing are included as recipients in another similar one.

Note: We are connected to many of the top mailbox provider feedback loop programs which enables us to automatically suppress email addresses which complain about specific mailings.

Suggested actions

  • Build mailings and newsletters with related topics and content to help recipients identify which they would like to receive.

  • Build the proper email or newsletter template structure to ensure opt-out processes for specific mailings are handled according to the correct hierarchy.

The email volume is exceeding the receiving mail server’s limits or capacity.

Possible cause: Sending too much/too fast

We may be exceeding the mailbox provider's traffic thresholds. Sending too much or too fast is associated with spamming and can result in temporary or permanent blocks.

Suggested action

Our team of email specialsts maintain proper throttling with the mailbox providers in an attempt to eliminate this issue.

The email was blocked because of a security policy violation.

Possible cause: Sender identity problem

Your identifying information can’t be verified (reverse DNS or valid From and Reply To addresses).

Suggested Aation

Update your DNS entries. Validate your From and Reply To addresses to be sure they actually exist.

Possible cause: Excess volume

Your cumulative daily volume exceeds the number of emails allowed. (Some smaller mailbox providers limit inbound volume to protect their servers from SPAM).

Suggested action

Consider the percentage of emails you are sending to the provider and contact us if additional action is necessary. If necessary, spread volume you send to it over multiple days.

The email was blocked because Unknown User failures reached an unacceptably high level.

Possible cause: Stale data

Your list may contain a high number of undeliverable addresses if you haven't recently used it or if too much time's elapsed since you obtained the addresses. This is an important data point to review since it's one of the main reasons mailbox providers block email messages.

Suggested actions

  • While you should adjust the frequency of your messages according to your recipients' preferences, you should also review all segments of your list on a regular basis to ensure brand visibility, continuity of communication, and address deliverability.

  • Set standards for the first communication after you obtain an email address (5 to 10 days). This reduces the liklihood the recipient will complain later.

  • If you mail to an "old" segment, do a test before full you send to the full list. Send the mailing to a subsets of the group to avoid spikes in Unknown User failures.

Possible cause: Poor data capture

You may not be adequately validating email addresses at the point of data capture.

Suggested actions

  • Send a follow up email to new recipients to confirm opt-in permission and validate the deliverability of the address they provided. If it bounces for reasons that indicate the address is invalid or inactive, remove the email and contact the recipient for a new or corrected address.

  • Require double entry of email addresses to minimize typographical errors.

  • Perform address hygiene to correct common misspellings on major domains before you add large quantities of new records to your list. After you correct addresses, send confirmation emails to verify the changes are accurate.

Possible cause: Unreliable data source

When you purchase email lists, you risk introducing undeliverable records to your list.

Suggested actions

  • Know your data sources. Investigate their data compilation and management practices and confirm consent and deliverability before incorporating their addresses into your list.

  • Perform address hygiene to correct common misspellings on major domains before you add large quantities of new records to your list.  After you correct addresses, send confirmation emails to verify the changes are accurate.

  • Contact the recipient for a replacement email address.

Possible cause: Failure to invalidate

You may not have invalidated previously identified Unknown User failures and removed them from your list.

Suggested action

Verify that Unknown User failures are properly invalidated and removed from your list. If not, immediately do so.

Mailbox providers use authentication methods to evaluate whether messages that appear to be from your organization are legitimate so they can block or filter email from fraudulent senders.

Possible cause

Your identifying information can't be verfied by an SPF record because of an invalid record or no record at all.  Your DomainKeys signature has not been properly configured in your email and DNS servers, or is not configured at all.

Suggested actions

If you are the system administrator for the domain, verify that the authentication record for it lists the Blackbaud servers as authorized to send email on its behalf.