Attach files to a campaign
Send a price list, a handbook or an agenda with your campaign, and give every recipient their own PDF built from a template and their own contact fields.
A campaign can carry two very different kinds of attachment, and Mailsoftly keeps them in one card so you never have to wonder which one you are looking at. Shared files are the same for everybody: the price list, the handbook, the agenda. A personalized attachment is one PDF per recipient, built at send time from a saved template and that person’s own contact fields.
The card is called Attachments, it sits near the bottom of the Campaign Details tab, and the line in its head is the answer to "is anything attached to this".
Attachments are switched on per account by our support team; if you do not see the Attachments card on the campaign page, ask support to enable it.
Find the Attachments card
Open a campaign that is still a draft and scroll the left column of the Campaign Details tab past the setup rows and the email footer. Attachments is the card underneath.
The head of the card carries a running summary. With nothing on the campaign it reads "Nothing attached yet". Add things and it counts them: "1 personalized PDF", "1 shared file", or both joined together, "1 personalized PDF · 2 shared files". The line is recalculated the moment you upload, remove or swap something, so it is never stale.
That summary exists for one reason. The two sections have separate empty states, and an empty Shared files section used to read as an empty campaign even when every recipient was getting a personalized attachment. The head tells the truth about the whole card.
Open your draft campaigns in Mailsoftly
Add shared files
Shared files is the first section, under the line "The same files go to every recipient." Press Add files, pick one or more from your computer, and each one appears as a row with its name and size, a download button to check what you uploaded, and an x to take it off again.
There is one limit to know: the total size of everything attached to a campaign. Go over it and Mailsoftly refuses the upload with the cap named, "Total attachment size cannot exceed 10 MB." for an account with a 10 MB cap. The number belongs to your account, so check what yours says rather than assuming.
Keep an eye on that total for a second reason. Big attachments are a deliverability drag, and a heavy email is more likely to be filtered than a light one with a link in it. If a file is large, consider sharing a file link in your email instead of attaching it.
Add a personalized attachment
The second section is Personalized attachment, described as "One PDF per recipient, filled in with their details." Instead of a file you choose a saved email template, and Mailsoftly renders it to a PDF once per message with that person’s merge fields filled in.
Press Choose a template, pick the letter, certificate or statement you designed, and the section changes shape:
- The template appears as a card with a live thumbnail. Clicking the card opens the PDF preview, and the meta line under the name says so with an eye icon reading Preview PDF.
- The quiet Change chip on the right of that card is the only control that swaps the template. Remove, in the section head, takes it off the campaign.
- Under the card sits File name, with a fixed .pdf chip on the end. Merge fields work here too, which is the point: "Thank You {(first_name)}" arrives in each inbox as that person’s own file name. The hint under the field says the same thing. A file name pattern can run to 120 characters.
- Delivery, directly under the file name, decides how the PDF travels. Attach the PDF puts it on the email. Secure link sends each recipient a personal link instead, and they confirm details on file before the PDF opens. Secure link is selected for every newly chosen document unless an admin made Attach the PDF the account default.
- A green note closes the section, and its wording follows the delivery. With Attach the PDF it reads "Each recipient gets their own PDF, built from this template with their details when the campaign is sent. Nothing is stored." With Secure link it says the document is kept privately while each person’s link works and removed a set number of days after it stops.
Take that note literally. With Attach the PDF, the document exists only inside the process that sends the message and is not written to storage, so the only copy is the one in the recipient’s inbox. With Secure link, the PDF is kept encrypted in private storage while the link works, alongside a record of the link and a fingerprint of the file, so you can see who opened it and resend it; the stored file is removed on schedule after the link stops working. Send documents by secure link covers that delivery, and Protect documents with an access code covers password protection, which only the secure link offers.
Check a recipient’s document
Click the template card and the PDF preview opens. It does not open on "the first row of the list": Mailsoftly picks a recipient who actually has a first name, so the merge fields show filled rather than blank.
From there you can walk the whole list. The header carries the recipient’s name and address, a counter reading something like "1 of 4089", and previous and next buttons. The search box finds anyone by name or email. Open in new tab hands you the raw PDF if you want to save or print it.
Each step is a real render on our side, so the modal says "Building the PDF for Amelia Carter…" for a moment before the document appears. If one recipient’s document cannot be built, the modal says so for that person and offers Try again, rather than pretending it worked.
Check three people, not one: somebody with every field filled, somebody missing the field you are least sure about, and somebody with the longest name on the list. A merge that looks perfect on a complete record is usually fine everywhere; the empty cell is what catches people out.
Know the limits
Four things decide whether this works for a given campaign.
- Attachments are switched on per account by our support team; if you do not see the Attachments card on the campaign page, ask support to enable it. There is no self-serve switch for it.
- Personalized attachments are available for lists of up to 5,000 recipients. Past that the section refuses and says so. If a list grows past it by send time, an attached send goes out without the documents, and a secure link send skips everyone.
- The upload cap counts the total of your shared files. Each personalized PDF is checked on its own: it must be under your account’s attachment size limit, and it is not added to the shared files’ total.
- The personalized attachment can only be edited while the campaign is a draft. On a scheduled or sent campaign the section is read-only, like the rest of the setup.
One more thing worth knowing before you rely on it. If a document cannot be built for one recipient at send time, what happens depends on the delivery. With Attach the PDF, that message still goes out, with the shared files on it and no personalized PDF, so the send is never held up by one bad render. With Secure link, that recipient gets no email at all, because a link is never sent without its document. Either way, a spot check beforehand is worth the two minutes; Create and preview personalized PDFs covers the preview in depth.
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