It is possible to add attachments to your email campaign with Mailmeteor. To add files attachments, create a new template and click on the attachment icon as shown below:
To attach larger files in your email, we currently recommend you to add a Google Drive link in your template. That will allow you to send files over 4MB, as well as make personalized files sending to your recipients.
Upload file to your Google Drive
Select file and right click on it
Click Get shareable link.
Make sure that the "Anyone with the link" options is active.
Copy the link
Add the link to your Mailmeteor template