We have observed that, CTA task email is failing to send because one of the tokens (CTA comments) which needed to be replaced was longer than 10k characters (including the special characters since it is a rich text field and seems to have been copied from some other place). In this scenario, below is the current failure message:
Hello <User Name>
This message was created automatically by mail delivery software.
An error occurred while trying to deliver this email to one or more recipients. The following address(es) failed:<Email ids>
The above failure message is not clear to identify the exact issue from customer end and we need to improve this messaging in the failure case.
Kindly review and add the below message for this type of failure scenario.
Mapped field value has exceeded the maximum character length allowed for tokens.