The interests.me system doesn't support attachments, in line with most bulk emailing services.
This is because it's quite heavy on the processing power, and it also increases the chances of the receiving email provider marking the email as 'spam' and not delivering it.
If it's a photo you want to attach, our tool does enable you to upload the photo and make it appear in the body of the email which is much easier to see.
We advise anyone who wants to send other attachments (eg pdfs) to save the pdf in a cloud storage provider (such as Dropbox, Google Drive, or OneDrive) and create a link to the place where it is saved, which can be pasted into the email. This ensures everyone can see the document just by clicking on the link, but it doesn't clog up people's inboxes.