Introduction
This instruction manual is designed to guide you through the configuration, use, and troubleshooting of Trustifi Email Relay within Microsoft Exchange Online via Office 365.
The document includes all necessary requirements, step-by-step configuration procedures, usage guidelines, and troubleshooting recommendations to ensure a successful deployment.
Please follow each step carefully and pay close attention to all warning notes throughout the process.
Requirements
To configure your email environment to work with Trustifi Email Relay, you must have:
An Office 365 administrative account with permissions to access and manage the Microsoft Exchange admin center
A Trustifi account with administrator permissions
Administrator access to your DNS management system
Troubleshooting
TLS Authentication Failed
Detailed Log
Couldn’t validate the recipient’s email server certificate. The certificate isn’t signed by a trusted certificate authority.
Solution
The incorrect certificate was selected. Please return to the relevant security settings step in the configuration guide and select the appropriate certificate.
Email Error
Detailed Log
The email you specified is an Office 365 mailbox. To validate this connector, please specify an email address that is not hosted in Office 365.
Solution
Use an email address that is not hosted in Office 365, such as Gmail, Yahoo, or Hotmail, and retry the validation step.
Domain Does Not Exist
Detailed Log
550 X.X.XYZ DNS domain bad-domain.com does not exist
Solution
This indicates an incorrect smart host address. Please return to the smart host configuration step in the guide and update the value accordingly.
Failure to Send a Message
Description
Messages are failing to send through the connector.
Solution
Review all configuration steps prior to connector validation to ensure each item was completed correctly.
Emails Sent Without Styles or Formatting
Description
Emails are delivered using RTF formatting instead of HTML, resulting in missing styles or formatting.
Solution
Disable Rich Text Format as instructed in the Remote Domains configuration step of the guide.
Automatic Replies or Forwarding Not Working
Description
Automatic replies, automatic forwarding, or Out of Office messages are not being processed.
Solution
Refer to the Remote Domains configuration step to enable external and legacy Out of Office replies.
Meeting Invitations Missing Reply Options
Description
Meeting invitations are delivered but do not contain Accept or Decline options.
Solution
Enable Out of Office and related functionality as instructed in the Remote Domains settings.
Email Sent Without the Trustifi Connector
Description
The message was sent and delivered but did not pass through the Trustifi secure connector.
Symptoms may include
Missing email wrapper
No Trustifi logo, footer, or header
Attachments delivered directly instead of as secure links
Links without tracking
Solution
This typically indicates a misconfigured mail flow rule or interference from other higher-priority rules.
Review and validate all rules and ensure the Trustifi Outbound rule is prioritized correctly.
Email Failed to Be Delivered
Description
The message was sent through the Trustifi connector but could not be delivered.
Solution
Validate the relay key in the message header as described in the mail flow rule step of the configuration guide.
If the configuration appears correct, contact Trustifi Support.
New Users Receiving “Welcome” Emails from Trustifi
Description
After the Email Relay connector is established, new users may receive a “Welcome” email upon sending their first message. This feature is optional.
Solution
Log in to the Trustifi Web Portal as an admin
Navigate to Outbound Management → Plan Settings
Select the Email Flow Integration tab
Scroll to Send welcome email to new users
Disable the toggle
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Issues with Delivering Emails to Groups
Description
Emails sent to distribution groups or aliases may fail delivery or may be delivered multiple times.
Solution
Log in to the Trustifi Web Portal as an admin
Navigate to Outbound Management → Plan Settings → Integrations tab
Select the Microsoft Exchange integration
In the pop-up window, locate the Groups/Aliases section
Click Sync to refresh the group and alias mappings
Issues with Encrypting Attachments
Description
Attachments are being encrypted automatically even though no DLP rules were triggered.
Solution
Log in to the Trustifi Web Portal as an admin
Navigate to Outbound Management → Rules and Policies → Policies tab
Scroll to the Attachments Encryption Policy section
Adjust the setting according to your organization’s requirements
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Third-Party Signature Service Isn’t Working
Description
When using a third-party signature solution such as Exclaimer Cloud, signatures may not be applied after integrating Trustifi.
Solution
To ensure signatures are applied correctly:
The signature service mail flow rule must appear before any Trustifi mail flow rules in Exchange.
The signature service rule must have Stop processing rules enabled.
If you are using Trustifi for both outbound and inbound protection along with a third-party signature service, all three mail flow rules must have Stop processing rules enabled.
Correct Mail Flow Rule Order
Signature Service Rule (e.g., Exclaimer Cloud)
Trustifi Outbound Rule
Trustifi Inbound Rule
If the issue persists, contact Trustifi Support at [email protected].
Frequently Asked Questions
Will the Email Relay apply to everyone in my domain?
Only if you want it to. During configuration, you can choose whether Email Relay applies to all users, specific groups, or selected individuals.
Does the Email Relay affect my incoming emails?
No. Email Relay only applies to outgoing email traffic. For inbound protection, refer to the Inbound Relay integration guide.
Will the Email Relay automatically encrypt all my emails?
No. Emails sent via Email Relay travel over a secure channel, but content is only encrypted based on your configured DLP rules and policies. See the DLP rules policies guide for more information.
Will the Email Relay automatically encrypt all my attachments?
This depends on your attachment encryption policy in Outbound Management → Rules and Policies → Policies tab.
I received a “Welcome” email from Trustifi. What does this mean?
It means a Trustifi account was created for you. You may create a password to access the Trustifi web app or Outlook add-in, but this is not required to send email via the relay.
Can I continue using the Trustifi Outlook add-in after enabling Email Relay?
Yes. The Trustifi add-in works seamlessly with Email Relay and can still be used for sending encrypted emails and viewing tracking information.
Is there a size limit for emails sent via Email Relay?
Email body limit: 6MB (including text, HTML, and inline images)
Attachment limit: 1GB