What inbox-to-day ratio do you use? Google vs Outlook comparison
volumeking · 2026-03-21 · 410 views
This topic comes up all the time in DMs so figured I'd start a proper thread. What's your sends-per-inbox-per-day limit for Google Workspace vs Outlook?
My current setup: Google Workspace inboxes at 15 sends per day. Outlook inboxes at 3 sends per day. I've tested higher on both and always see deliverability drop within 2-3 weeks.
Why the difference? Google is more lenient with sending volume because you're on dedicated infrastructure (especially through providers like PuzzleInbox where each inbox gets its own Google Workspace account). Outlook is shared infrastructure by nature — even with a paid account, Microsoft's anti-spam systems are more aggressive about rate limiting.
The math: With 20 Google Workspace inboxes at 15/day, you get 300 emails per day or about 6,600 per month (22 working days). With 20 Outlook inboxes at 3/day, you get 60 emails per day or 1,320 per month. To match Google volume with Outlook, you'd need 100 inboxes. The cost difference is massive.
I used the inbox calculator tool from Puzzle Inbox to model this out. At scale the economics heavily favor Google Workspace for cold email volume. Outlook has its place for certain use cases — some industries respond better to Outlook domains, and it diversifies your infrastructure — but for pure volume, Google wins.
Question for the thread: Has anyone successfully pushed Google Workspace past 20/day per inbox without deliverability issues? And what's the highest you've gone on Outlook before hitting problems?
Comments (4)
derek_outbound · 2026-03-21
I've pushed Google Workspace to 22/day for short bursts (2-3 weeks) without issues, but anything past that and I start seeing inbox placement drop on GlockApps tests. 15/day is the sweet spot for sustained sending over months. not worth the risk going higher for the marginal volume
multichannel_m · 2026-03-21
on Outlook I've never gone past 5/day without getting throttled within a week. the 3/day number is real. we use Outlook purely as a secondary channel for prospects who don't respond to Google — helps with the "different sender, different provider" approach. but for primary volume it's Google all day
scalefast · 2026-03-21
the cost math is what convinced me to go almost entirely Google. we ran the numbers: 40 Google inboxes at 15/day = 600 sends/day. to get that same volume on Outlook at 3/day you need 200 inboxes. even if Outlook inboxes are cheaper per unit the total cost is way higher for the same output. only exception is if you're targeting industries where Outlook domains look more "enterprise" (legal, finance, etc)
volumeking · 2026-03-21
appreciate all the data points. seems like the consensus is 15/day Google and 3-5/day Outlook. I'm going to stick with 15 on Google and bump Outlook from 3 to 4 and monitor closely. will report back in a couple weeks with deliverability data