We read a stack of "email deliverability" job postings this month. The surprise wasn't that companies are hiring for deliverability — we already knew they were. It was what they keep asking the hire to fix.
A veterinary-software company wants someone to own "deliverability issues, list hygiene, sender reputation." A DTC sports-commerce brand lists "bounces, complaints, sender reputation." A document-workflow platform running email at 100K+ scale needs "list health across four products." A supplements brand leads with the number that says it all: "1M+ email subscribers." Different industries, same quiet admission — the list is the job.
That cuts against the reflex. When mail starts landing in spam, teams reach for the sender side: SPF, DKIM, DMARC, IP warming. All necessary. None of it saves you if you're sending to a bad list. Mailbox providers grade you on who you send to and how they react — not just how cleanly the message is signed. You can run a flawless authentication setup and still wreck your reputation on addresses that bounce, complaints that pile up, and contacts who stopped opening a year ago.
And a list goes bad quietly. Email addresses decay at roughly 2% a month as people change jobs. Abandoned addresses get recycled into spam traps. One enthusiastic import drops a few hundred role accounts and typos into your file. None of it shows up in your ESP's green dashboards — until your inbox placement has already slipped and you're reverse-engineering why.
That's the other half of deliverability, and almost nobody checks it before a send — because checking has always meant handing your customer list to a vendor.
So we built the check to run without the upload.