Nobody's problem is producing the contract. The problem is the eleven days between sending it and getting it back, most of which you spend deciding whether today is too soon to follow up again.
That delay is nearly always friction, not reluctance. Fix the friction and documents come back the same day.
Send a link, not a file
The instinct is to attach the PDF. It's the worst move available.
An attachment is a copy that leaves your control the moment it sends. You can't tell whether it was opened. You can't correct a typo without creating a second version in the wild. And whatever comes back arrives however the other person managed it: a photo of a page, a re-typed name, a different file entirely. You end up doing document reconciliation instead of business.
A link keeps one document. The other party opens it, signs in their browser, and what returns is the same document with a signature and a record of the exchange attached. You can see it was opened. You know exactly which version was signed.
Email works, if it reads well on a phone
Most people read email on their phone. Write the signing email for that screen, not for a desk.
Keep it short enough to read without scrolling, and put the link near the top instead of under three paragraphs of pleasantries. A link that opens in the phone's browser gets signed in the same minute: no download, no PDF app, no attachment to find later. Most of the "clients are slow to sign" complaint disappears the first time the signing happens on the phone the person is already holding.
Email also gives you the record. The request sits in their inbox and in yours, and when the signer is a business it can go straight into their procurement trail. If you mostly deal with the person by phone, a quick call or message to say the email is on its way does no harm.
Write the message so it gets opened
The covering message does more work than people give it credit for. Three things belong in it: what the document is, what you need them to do, and by when.
Compare "Hi, please find attached the quote for your review, kind regards" with "Hi Thabo, here's the quote for the Sandton install, R14,200. Tap to sign and I'll book the team for Monday." The second one tells the person the number so they don't have to open anything to know if they care, tells them exactly what the action is, and gives them a reason to do it now rather than later. It also reads like a person wrote it.
Say the amount. Hiding the figure inside the attachment doesn't help you.
Chase properly, twice
Send the document, then leave it a couple of working days. One short nudge. A few more days, one more nudge, and this one should offer to talk rather than just repeat itself.
After that, stop reminding and start asking. A quote that's had two prompts and no response isn't a paperwork problem. Something about the price or the timing isn't landing, and another reminder won't surface it. The conversation will.
If you're sending a link rather than an attachment, you have information the reminder can use: whether it was ever opened. Someone who opened the document twice and didn't sign is a different conversation from someone who never opened it at all.
Keep what comes back
When it's signed, keep the signed PDF, the version that was signed, and the record of the exchange. Filing only the final PDF loses the part that proves who signed it.
E·BIZI Papers is built for exactly this loop: design the quote or contract once, email a link, and the signed PDF comes back with a certificate of completion that shows who signed and when. No attachment ping-pong.