NotifyLink On Demand servers have an attachment size limitation.  For NotifyLink users, this means that attachments larger than approximately 2.5-3 MB will not be available for download on the device. This size is handled per-attachment, not cumulative for all attachments on a single email.  For example: 3 attachments each 1 MB in size should process successfully but 1 attachment 3 MB in size likely will not.

Most attachment are Base64 encoded, which increases the file size by 33%.  Therefore if you send a 720 KB document as an attachment, the attachment will be 960 KB.

The attachment size limitation is adjustable for On Premise customers only.