PDF attachment vs. link: which should you send?

You finish the proposal, attach the PDF, hit send — and then nothing. Did they open it? Did it land in spam? Did the 18 MB file even go through? Attachments go silent the moment you send them. Links don't. Here's an honest comparison of both, including when the attachment is still the right choice.

Where attachments quietly fail

• Size limits.Gmail caps attachments around 25 MB, Outlook around 20 MB — and encoding inflates files ~33%, so a "19 MB" PDF can still bounce. Image-heavy decks and brochures hit this constantly.
• Spam filters like them less.Large or unusual attachments raise the odds of landing in spam, especially when you're emailing someone for the first time — which is exactly when proposals get sent.
• No undo, no update.Spot a wrong price after sending? The old file lives in their inbox forever. Your only move is the "please ignore my previous email" email.
• Zero feedback.You can't tell an ignored email from a read-and-shortlisted one. Your follow-up timing is a coin flip.

What changes when you send a link

• It always arrives.A link weighs nothing — no bounce, no clipping, no "file too large." The email itself gets lighter and cleaner.
• You see the opens. A trackable link counts views. Two opens from two devices this morning? That proposal is being discussed. Follow up today, not next week.
• You can fix the file after sending. Replace the PDF behind the link and every copy of that link — in every inbox — now opens the corrected version.
• You stay in control.Password-protect it, make it view-only, set an expiry date, or kill the link when the deal closes. An attachment obeys nobody once it's sent.

When an attachment is still the right call

Links aren't always the answer. Send an attachment when:

• The recipient must archive the file— invoices, contracts, and compliance documents often need to live in the recipient's system, not behind your URL.
• Policy blocks external links. Some corporate and government mail systems distrust links more than attachments. Know your audience.
• It's tiny and final. A 200 KB signed one-pager that will never change? Attach it. The overhead of a link buys you nothing there.

The practical rule

How to send a PDF as a link

Upload the PDF to Link in Seconds, copy the clean URL, and paste it in your email. The recipient opens it in their browser — no account, no download required — and you see every view in your dashboard. If the file changes, replace it and the link keeps working. Start with the free plan on the Share a PDF online page, or read how founders use it for proposal tracking.