The question sounds like "how many can I register," but the real answer starts elsewhere: how the counter works, and why gaming it just postpones the problem. A per-domain limit isn't a form-field restriction — it's a fraud-detection signal. Here's why services count accounts by domain, what happens once the limit is crossed, and how to run multiple accounts legally: by separating them into isolated contours, not gaming the counter.
Why services count accounts by domain
A per-domain counter defends against three kinds of abuse. Inflated activity: mass-registering behaviorally identical accounts skews platform metrics and opens the door to gaming ratings, votes, and referral programs. Spam and abuse: the more accounts under one hand, the easier it is to push unwanted content or dodge a ban on one account by registering the next. Trial-period abuse: a free trial is sized for one new user, not an endless chain of signups meant to keep extending it. A domain is the cheapest grouping signal a service has: addresses on it almost always trace back to one point, and infrastructure metadata — signup IP, request timing — gets scored per group, not per address. A different tag before the "@" doesn't fool the fraud system: it's still the same domain, the same group.
What happens once you cross the limit
Gaming the limit is almost never a clean win — it's a temporary result with a delayed cost. First, new signups from that domain start getting rejected: the system flags the pattern once and acts on autopilot from then on. Worse: accounts created earlier can pick up restrictions retroactively, when the fraud system re-scores the whole domain and applies the decision to the entire group at once. An account that looked fine for weeks can lose functionality overnight — not because of anything it did, but because of its neighbors on the domain. Gaming the counter solves the signup problem and puts continued access at risk.
When several accounts are normal, and how to separate them correctly
Owning multiple accounts isn't a violation — what matters is whether they're separate, independent use contexts, not one chain dressed up as several identities. A personal and a work account, several employees at one company on the same platform, a test setup kept apart from production — this is ordinary practice: a real, distinct task sits behind each account, not an attempt to multiply the same activity.
Proper separation means different domains for different contours, not tags on one address: plus-addressing solves inbox filtering inside a single mailbox, but not separation in front of a service, because those addresses still share one domain. The trade-offs are covered in email alias or a separate mailbox: pros and cons; which domain to pick for a new contour is in how to choose an email domain for registration.
The practical rule: if two accounts need to stay independent from a service's point of view — personal and work, yours and a client's, production and test — each needs its own address on its own domain, not a variation on the same one. This is the same separation companies already apply to access and passwords, applied to email. A broader look at separating communication contours is in separating personal and work: a dedicated communication setup.
What the platform provides, and where it stops
For a one-off task — confirming a signup on one site — the platform issues a temporary address from a shared domain pool for that site: the mailbox stays open for 20 minutes, and if the code doesn't arrive, the activation closes automatically and the charge is refunded. For a recurring task — a working contour — there's a mailbox rental from 12 hours to 60 days with the option to extend; ordering it means declaring, up front, the list of sites it will accept mail from. Domains come from the platform's pool — you can't attach your own: a deliberate design choice, not a gap. It's a genuine tool for separating contours, not a way to dodge one service's limits.
Frequently Asked Questions
Can you beat a domain-based limit by changing what's before the "@"?
Technically, yes — but it doesn't solve anything: to a service grouping activity by domain, that's still the same node. The only reliable separation is different domains for different contours.
What does a user lose if they cross the limit and get hit with retroactive restrictions?
Access to accounts that may have worked fine for a while: the restriction applies not just to new signups but retroactively to the whole group once the fraud system re-scores the domain as a whole.
Do I need a separate domain for a test setup if I already have a production account?
Yes, if the test setup needs to stay independent from production — so a restriction or ban on the test account doesn't touch the working one. Same principle as separating personal from work.
You can order a one-off activation for a specific site, or a mailbox rental for an ongoing working contour with your own sender list, in the email-OTP section.