Email sending errors in Uku: causes and solutions
When emails fail to send from Uku, you can identify the cause, fix the issue, and resend failed emails either one by one or in bulk. This guide covers the most common email errors and how to resolve them.
Who can do this
Any Uku user who sends emails through the platform
Administrators with access to Settings > Emails (for bulk resend and outbox management)
Common causes of email failures
Emails may fail to send from Uku for several reasons:
Expired integration token (Google or Microsoft)
Expired or changed email password
Typo in the recipient email address
Incorrect or outdated email settings
Email account limitations or quotas
Exceeding email service provider send limits
When Uku cannot send an email, a notification appears in the Uku notification center. If send limits are exceeded, Uku automatically re-routes emails through its secure mail server to ensure delivery.
Missing emails and spam filtering
Emails may reach the provider but not appear in the recipient's inbox due to spam filters. Email services like Outlook may mark legitimate emails as spam or redirect them to the Junk folder.
To resolve this:
Ask the recipient to check their Spam or Junk folder.
If found, mark the email as Not Spam or move it to the main inbox.
Review any filtering or quarantine rules in the recipient's email settings.
Add Uku's sending domain to the recipient's email whitelist to prevent future issues.
How to resend emails one by one
Click on the error notification in the Uku notification center. You will be redirected to the task where the email failed.
The task displays an error message. Click on it to see the reason for the failure.
Fix the underlying issue (for example, update the integration, correct the password, or verify the email address). If reconnecting, ensure the email account is properly configured with updated credentials.
Navigate to the client card by clicking the star icon next to the client's name.
On the client card, open the Communication tab.
Find the failed email in the list and click Resend next to it.
How to resend all failed emails at once
Open the email outbox using one of these methods:
Go to the client card and select Email Outbox, or
Go to Settings > Emails > Tools tab, then click Outbox for emails.
In the outbox view, apply filters using the filter bar:
Select the appropriate date range
Select the company
Set email status to Error
Optionally choose a specific client
Click the refresh icon to load results.
Fix the issues that caused the errors (such as reconnecting an expired integration).
Select the emails you want to resend.
Click Send failed emails, confirm your selection, then click Send all.
Only emails with Error status that are related to automated sending can be resent using the bulk method.
Email status definitions
Warning — Shown only for failed emails related to Client Portal messages. If these cannot be sent via integration, they are redirected through uku@getuku.com.
Sent — Emails that were successfully delivered.
Error — Emails that failed to send (for example, due to an expired integration or changed password).
Preventative tips for stable email delivery
Monitor email send volumes and stay within your email provider's limits.
Encourage recipients to add your email address to their safe sender list.
Periodically validate email client settings to ensure legitimate emails are not flagged as spam.
Whitelist Uku's domain in your email server or client settings.
Troubleshooting
Resend button does not appear for a failed email: Only automated emails with Error status can be resent. Manually composed emails must be re-created and sent again.
Emails keep failing after reconnecting the integration: Verify that the reconnected account has the correct permissions and that the email password has not changed again. Try disconnecting and reconnecting the integration.
Recipient says they never received the email even after successful send: Ask the recipient to check their Spam, Junk, and quarantine folders. Have them whitelist Uku's domain.
Bulk resend does not include all failed emails: Check your date range and status filters. Only emails matching the applied filters and with Error status appear in the list.