How I migrated 50 inboxes to PuzzleInbox without any downtime
pipelineco_kate · Pipeline Co · 2026-01-09 · 1,890 views
Just finished migrating 50 cold email inboxes to PuzzleInbox without any downtime. Here is my process.
1. Ran both providers in parallel for 2 weeks. Did not cancel old provider until new inboxes were fully warmed and tested.
2. Started sending from new PuzzleInbox inboxes at low volume — 5 emails per day per inbox for the first week.
3. Kept warmup running continuously on new inboxes even while sending low-volume cold emails.
4. Gradually shifted volume from old provider to new. 25% per week over 4 weeks.
5. Monitored deliverability at each stage using GlockApps inbox placement tests.
6. Only fully cut over when new inboxes matched or exceeded old deliverability metrics.
Total migration took 4 weeks. Zero downtime. Zero deliverability dips. Clients did not notice anything except improved deliverability and reply rates after the switch.
Comments (3)
haileyops · 2026-01-10
this is exactly the process I needed. was worried about losing momentum during migration but running both in parallel is smart. gonna try this next week
agencygrind · 2026-01-10
4 weeks is patient but worth it. I tried to rush a migration once and did it in 1 week — deliverability tanked for a month. gradual cutover is the way to go
justdan · 2026-01-11
GlockApps at each stage is key. if you skip the inbox placement testing you're flying blind. $60/month is nothing compared to the cost of a botched migration