Dear Stakeholders,
As we continue preparations for our transition to Ontario Dig Authority on October 1, 2026, we are sharing important information to help ensure uninterrupted delivery of critical operational communications.
As part of this transition, we will be introducing a new email domain for delivering critical operational notifications related to locate requests, ticket activity, underground infrastructure communications, and other service-related notices.
This rebrand reflects our continued commitment to protecting underground infrastructure and supporting safe excavation across Ontario. While our name and visual identity are changing, our mandate, services, and dedication to our stakeholders remain unchanged.
Actions Required
To avoid disruption in receiving critical notifications, please ensure your IT and email administration teams update any email security, filtering, or safelisting configurations before October 1, 2026.
Please add the following to your email safelists or safe sender lists:
- New Sending Domain: ontariodigauthority.ca
- Mailgun Sending IP Address(es): 198.244.48.198
In some cases, notifications may continue to be sent from existing Ontario One Call email addresses during a transition period to ensure a smooth migration.
Organizations using Microsoft 365, Exchange Online Protection, Proofpoint, Mimecast, Barracuda, Cisco Secure Email, or similar email security solutions should review any mail flow rules, anti-spam policies, or sender filtering configurations that could affect message delivery.
Why This Is Important
This email is for critical operational communications and is NOT a marketing or promotional message.
They may include:
- Locate request notifications
- Ticket updates and status changes
- Underground infrastructure notifications
- Damage prevention communications
- Service alerts and operational notices
Ensuring these notifications are received is important, as they support your organization’s ability to respond to locate requests and other time-sensitive infrastructure-related activities.
Email Authentication and Security
To help ensure secure and reliable delivery, the new domain will be configured with industry-standard email authentication measures, including:
- SPF (Sender Policy Framework)
- DKIM (DomainKeys Identified Mail)
- DMARC (Domain-based Message Authentication, Reporting and Conformance)
Review Inbox and Mail Processing Rules
If your organization has configured inbox rules, mail flow rules, shared mailbox rules, distribution lists, ticketing integrations, or automated workflows that identify Ontario One Call notifications based on the sender’s email address or domain, these configurations may need to be updated as part of our rebranding transition.
Please review and update any rules or processes that reference:
Current Domain
@On1Call.com
New Domain
@OntarioDigAuthority.ca
Examples may include:
- Microsoft Outlook inbox rules
- Shared mailbox routing rules
- Microsoft 365 Exchange mail flow rules
- Help desk or ticketing system integrations
- Distribution group forwarding rules
- Email archiving and retention policies
- Automated workflows and monitoring systems
It is important that organizations take the necessary steps to prepare their systems and update these configurations to ensure notifications are routed and processed as intended and do not go unnoticed in user mailboxes.
We appreciate your assistance and cooperation during this transition. Thank you for helping ensure the continued delivery of critical locate and infrastructure notifications.
