Nobody plans to email the same person four times on a Tuesday. It happens anyway: the product webinar invitation, the nurture touch that was already scheduled, the field event follow-up from another region, and the newsletter — four teams, four calendars, one inbox. The recipient doesn't see four well-intentioned programs. They see a company that won't leave them alone, and the closest button is "Report spam."
Communication limits are the platform-level guardrail against exactly this. In Marketo the setting is literally called Communication Limits; HubSpot, Pardot/MCAE, and most other platforms have an equivalent frequency cap. It's one of the highest-leverage settings in any instance — and one of the most commonly left at "off," because turning it on requires decisions nobody wants to own. Here's how to make those decisions.
What the setting actually does
A communication limit caps how many emails a single person can receive from your instance per day and per week. When a send would exceed the cap, the platform blocks that person from receiving it — the campaign still runs, the over-limit recipients are simply skipped (and logged, so you can see who was protected and from what).
Two design details matter. The limit is per person, not per campaign — which is the whole point, since no individual campaign ever looks excessive on its own. And it's enforced at send time, which means it acts as a safety net under every calendar conflict, cloning mistake, and cross-team collision that your planning process didn't catch.
Picking the numbers
There's no universal right answer, but there's a defensible starting point for B2B: 1 per day, 3 per week for marketing communications. That accommodates a weekly rhythm — a nurture touch, a campaign send, a newsletter — while making a four-email Tuesday impossible.
The wrong way to pick numbers is to ask each team what they need; the sum of everyone's needs is how you got here. The right way is to start from the recipient: how many marketing emails per week from one vendor feels like a relationship rather than a siege? Set the cap there, then make the teams negotiate calendar space within it. The cap turns frequency from an unowned side effect into a shared budget — which is exactly the fight you want teams having in a planning meeting instead of in the recipient's inbox.
If your database segments have genuinely different tolerances — active trialers versus a cold re-engagement pool — most platforms let you handle this by exempting specific high-intent programs rather than raising the global cap. Keep the global number conservative; grant exceptions deliberately.
The exemption decision: operational yes, "important" no
Every platform lets individual emails or campaigns bypass the limits. This is where good caps go to die, because every team believes their send is the important one.
A clean rule: operational emails are exempt; marketing emails are not — no matter how important the campaign feels. Operational means the recipient asked for it or needs it: registration confirmations, webinar reminders for something they signed up for, password and billing notices, unsubscribe confirmations. Blocking those because a newsletter went out this morning would be absurd, and platforms flag them as operational precisely so they bypass caps (and, depending on platform, unsubscribe status — so classify carefully and lawfully).
Everything else queues within the cap. The moment "product launch" or "executive request" becomes an exemption category, the limit is decorative. If a send truly can't wait, the escalation path should be a human decision with a name attached — not a checkbox any program owner can tick.
What changes when you turn it on
Expect three effects. First, some sends shrink: campaigns start reporting "blocked by communication limit" counts, which feels alarming and is actually the system working — those were the people you were about to burn. Second, calendar conflicts surface early: teams competing for the same audience in the same week now find out at planning time. Third, and slowest: complaint rates drift down. With Google and Yahoo enforcing a 0.3% spam-rate ceiling for bulk senders, frequency governance stopped being a courtesy and became compliance infrastructure — the caps are one of the few levers that directly reduce the "too many emails" complaint, which is the single most common reason people hit the spam button on legitimate mail.
One honest caveat: communication limits are a ceiling, not a strategy. They stop the worst collisions; they don't make a bloated calendar sensible. If half your sends are getting blocked, the fix isn't raising the cap — it's the send calendar.
A 15-minute check for your instance
Three questions to answer this week: (1) Are communication limits actually enabled, and what are the numbers? In many instances the honest answer is "off" or "set once in 2019 by someone who left." (2) Pull last month's sends for a handful of engaged contacts — how many marketing emails did the busiest inbox receive in its worst week? That number is your current de facto policy. (3) Which programs are marked operational, and would every one of them survive a recipient asking "did I ask for this?"
If question two produces a number you wouldn't say out loud to a customer, the setting is worth an afternoon.
Send governance and frequency controls are part of what we check in a stack audit — one call, one week, one prioritized fix list, yours either way. For the full practice — deliverability, governance, segmentation, and lifecycle sends — see email marketing operations.