I have a very strange thing happening. I have an expense claim form which has an attachment control. Users have reported that some of the forms are not going to their manager for approval - the manager fails to receive a workflow email. (Upon form submission the initiator receives an acknowledgement email and then the workflow triggers an approval request to their manager).
After doing some testing it seems that if the form has an attachment that is approximately 1.2MB or bigger, the workflow email message fails to send. The Web app setting for max upload document size is 300MB. The form works perfectly well if the attachments are 1.1MB or under.
Does anyone know why this is happening?