Signatures are displayed in plain text format when emails are received


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.


The issue occurs because the message format has been changed from HTML to plain text during delivery of the message - after it has been processed by Exclaimer Cloud. This might happen for a number of reasons, but most commonly:

  • If Remote Domain configuration settings specified on the Microsoft Exchange server are incorrectly configured. For a solution to this issue, please click here.  
  • If the TNEFEnabled property is set to True, emails sent to providers who do not support 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. For a solution to this issue, please click here.


To check & configure remote configuration settings

Stage 1:

If you are using Office 365, connect using instructions below:

  1. Run PowerShell (as an administrator).
  2. Run the following command and enter Office 365 Administrator credentials:

$UserCredential = Get-Credential

  1. Connect to Office 365:

$Session = New-PSSession -ConfigurationName Microsoft.Exchange -ConnectionUri -Credential $UserCredential -Authentication Basic -AllowRedirection

If you are using an on-premise Microsoft Exchange server, connect using these instructions:

  1. On the Microsoft Exchange server, launch the Exchange Management Shell (EMS).


Stage 2: check remote domain settings

  1. To view the current Remote Domainconfiguration, run the following command:

Get-RemoteDomain | fl

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.


Stage 3: change remote domain settings

To change the ContentType property, run the following command:

Set-RemoteDomain -Identity <name> -ContentType <type>

Note: The identity <name> should be populated with the name of the remote domain specified on the Microsoft Exchange Server. By default, this is *. For example:

Set-RemoteDomain -Identity * -ContentType MimeHtml

To set the TNEFEnabled property

When this value is set to $Null (blank), which is the default setting, TNEF messages are not specifically allowed or prevented for recipients in the destination domain. Whether TNEF messages are sent to recipients in the remote domain depends on the specific setting on the mail contact or mail user, or the setting specified by the sender in Outlook.

  1. Follow instructions for stage 1 (above) to connect to Office 365.
  2. Run the following command:

Set-RemoteDomain * -TNEFEnabled $Null

For further information, please refer to this MSDN article.


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