Announcement: Email Delivery Issue Following Network Incident – 23 July 2025
Dear Valued Clients,
On 23 July 2025, a network incident caused a temporary spike in traffic that led our DNS upstream provider to mitigate resolver connections for domains using Exabytes’ default DNS.
This resulted in intermittent email delivery issues for some users. Clients using external DNS services such as Cloudflare were not affected.
Scenario 1: Failed A/MX Lookups
Impacts: Emails not delivered and website not accessible.
What Happened: Due to the DNS mitigation, servers were unable to resolve recipient domain MX records (used to route emails). This caused undelivered emails to accumulate and triggered the mail server’s deferral threshold.
Sample message for email: Domain A.com has exceeded the max defers and failures per hour (xx/xx). Message discarded.
Scenario 2: Post-Restoration Email Surge
Impacts: Sending Limit Reached. Some emails were temporarily deferred and automatically reattempted later.
What Happened: Once DNS connectivity was restored, users attempted to resend emails at the same time. This flood of outgoing traffic exceeded the server's hourly outbound email limit.
Sample message: Domain A.com has exceeded the max emails per hour (xxx/xxx, 110%). Message will be reattempted later.
Current Status:
Our upstream provider has restored DNS functionality. Email services are now operating as expected. Recommended Client Actions
1) Switch to Google Public DNS or Cloudflare Public DNS
2) Flush your DNS cache to ensure smooth email operation:
3) (Optional) Temporarily update your mail client to use the server hostname instead of the default domain in the incoming/outgoing server settings.
We appreciate your understanding and patience during this period. Should you experience any further issues, please reach out to our support team via support@exabytes.my
Warm regards,
Exabytes Team