Adding a UTM-tagged signature link took our cold-email reply rate from 4% to 11%
A small experiment from one of our customers. We rebuilt the signature, added one tracked CTA, and kept everything else the same. The numbers spoke.
Luka Doncic
· Growth lead ·
Apr 26, 2026
·
6 min read
The setup
A B2B SaaS doing cold outreach. Same SDR, same template, same target accounts.
What we changed
Replaced the existing text-only signature with a ProEmailSign Signature plan: photo, brand-coloured contact block, and a single CTA — "Book a 15-min intro" — UTM-tagged.
What happened
Reply rate climbed from 4.1% to 11.3% over a 30-day window. The CTA click-through rate was 6.8%, with the majority of clicks happening from mobile.
Why we think it worked
The signature gave the email a person — not just a name. The CTA gave the recipient something to do that wasn't "reply." Both are easy wins.
Written by Luka Doncic
Growth lead · ProEmailSign
