While there is not a de facto attachment size limit in PreVeil Mail, we recommend limiting the size of attachments to 75-100 MB in size for best performance in sending and receiving the message.
We would suggest using PreVeil Drive for file sharing instead as it is better able to handle sharing larger files and there is a built-in ability to set sharing permissions in Drive in a way that isn’t possible with mail attachments.
Please see: https://preveil.atlassian.net/servicedesk/customer/portal/2/article/318865532?src=-1719636891 for information on using PreVeil Drive.