Scenario
When a signature is appended by Exclaimer Cloud, in some scenarios, the recipient receives the email in plain text format. As a result, the signature is also displayed in plain text format rather than HTML.
Reason
The issue occurs because the message format has been changed from HTML to plain text during delivery of the message and after it has been processed by Exclaimer Cloud.
This can happen for a number of reasons, but most commonly:
- If the Remote Domain configuration settings specified on the Microsoft Exchange server are incorrectly configured.
- If the TNEFEnabled property is set to True, emails sent to providers who do not support Transport Neutral Encapsulation Format (TNEF) (for example, Gmail) will be displayed in plain text. The email will also be displayed in plain text if the recipient's email client does not support TNEF.
Resolution
Please click on the required options listed below to go through the detailed description:
To check and configure the Remote Domain configuration settings:
-
Open the Windows PowerShell and run this command as an Administrator:
Install-Module -Name ExchangeOnlineManagement
-
Confirm that you want to install this PowerShell module.
NOTE: For additional installation options, see ExchangeOnlineManagement.
- If you have Multi-Factor Authentication enabled, run this command:
Connect-ExchangeOnline -UserPrincipalName <UPN> -ShowProgress $true
In <UPN> enter your username. - If you don't have Multi-Factor Authentication enabled, run this command:
Connect-ExchangeOnline -Credential $UserCredential -ShowProgress $true
When prompted, enter your password (and the Multi-Factor Authentication verification code if required).
To view the current Remote Domain configuration, run the following command:
If the ContentType property is specified as MimeText, this is likely to be the cause of the message format being converted.
The ContentType property should be configured as either MimeHtmlText or MimeHtml, where:
- MimeHtml enforces HTML format.
- MimeHtmlText allows the receiving email client to decide the best format to display the message.
To change the ContentType property, run the following command:
For example:
To set the TNEFEnabled property settings:
-
Open the Windows PowerShell and run this command as an Administrator:
Install-Module -Name ExchangeOnlineManagement
-
Confirm that you want to install this PowerShell module.
NOTE: For additional installation options, see ExchangeOnlineManagement.
- If you have Multi-Factor Authentication enabled, run this command:
Connect-ExchangeOnline -UserPrincipalName <UPN> -ShowProgress $true
In <UPN> enter your username. - If you don't have Multi-Factor Authentication enabled, run this command:
Connect-ExchangeOnline -Credential $UserCredential -ShowProgress $true
When prompted, enter your password (and the Multi-Factor Authentication verification code if required).
Run the following command:
If you have a hybrid mail flow environment, you may also need to configure the ContentType and TNEFEnabled properties on your on-premise Exchange Server.