Rescuing sender reputation and leaving the playbook behind

Tagvenue runs a high-volume marketplace where onboarding, sales, finance and marketing all send mail daily across several tools and domains. Some of that traffic had drifted into spam, a sending IP had landed on blacklists, and authentication was incomplete, the kind of reputation dip that hits every large sender sooner or later. Nobody owned deliverability end to end, and there was no monitoring to catch the next problem early.

I treated this as recovery, not blame. Reputation is a signal you can rebuild once you understand what's dragging it down. I started with a full audit and seed testing to see exactly where mail was landing, then separated the sending into distinct streams so a problem in one channel could never poison the others. Every change was measured before and after, so the team could see what moved and why. The real deliverable was not a one-time fix but a set of routines the team can run without me.

1. 01

   Audit and seed tests

   I inventoried every mailflow (tools, domains, IPs and streams) and ran seed tests across the major providers to measure exactly where mail was landing versus spam. That gave a hard baseline instead of guesswork.

2. 02

   Root-cause diagnosis

   I traced the reputation damage to its sources: a blacklisted IP, incomplete authentication, and a misconfigured sending domain on the marketing channel. Then I prioritized the fixes by their impact on inbox placement.

3. 03

   Authentication and delisting

   I completed SPF, DKIM and DMARC across the sending identities and ran the delisting process to clear the blacklisted IP. That restored the trust signals providers check before deciding inbox or spam.

4. 04

   Stream separation and hygiene

   I split transactional, marketing and cold outreach into isolated streams on dedicated infrastructure, added a controlled IP warm-up, and put bounce and block handling in place so bad addresses stopped eroding reputation.

5. 05

   Monitoring and check-ups

   I set up reputation and blacklist monitoring plus a recurring delivery check-up run before large sends. Problems now surface early, while they're still cheap to fix.

6. 06

   Playbook handover

   I wrote the guidelines, dos and don'ts and sending discipline into a best-practices playbook and handed it to the team, so they keep reputation healthy long after the engagement ends.

Tagvenue came out with a clean, authenticated sending setup, its IP off the blacklists, and clearly separated streams that keep transactional mail protected from riskier marketing and outreach traffic. Just as important, the team now owns the monitoring, hygiene routines and sending discipline to catch issues early and scale volume without putting reputation back at risk. Deliverability stopped being a black box and became something they can see and steer.