No, you can not. And here are some of the reasons:
1. Including attached files to your sendouts may affect your deliverability.
Spammers often use attachments to their emails and this has of course resulted in a bunch of alarms over at the ESP's. Your emails may not reach your recipients and you may even get blacklisted and not get through at all which can affect your deliverability in the long run.
2. Even if you're passing the first spam check, some ESP's do block emails that are too big, so the full email size matters. Adding a file increases the size and the risk for being blocked.
3. The email size also affects the receiver as of longer loading time.
So, how to get around this?
Our recommendation is to add a link in your email to the file.
For files without personalized content, it's really easy and the file can be hosted either on your side (just add the URL to a link) or on the Symplify side (select link type File and upload your file).
If you have personalized content in your file you must host the files yourself and include some identifier in the filename to match the correct content with the correct recipient.
Let's say this is the unique URL's to each file on your side:
https://yourFileHost.com/files/originalId1.pdf
https://yourFileHost.com/files/originalId2.pdf
https://yourFileHost.com/files/originalId3.pdf
The URL to the file in your email should then be structured like this, with handlebars, in order to fetch the original id of each unique contact and build the URL at sending time:
https://yourFileHost.com/files/{{contact.originalid}}.pdf
For files with sensitive personalized content we advice you to host the files yourself and make them accessible for your customers when logged in on your site and guide your contacts to that location in you communication.