Acceptable use policy
Last updated: 18 August 2026
This policy forms part of the Terms of Service. It says what Bosun may not be used for, and — as far as possible — what the product does about it rather than what we would prefer you did.
Bosun is a shared inbox. It exists to help a team answer email that people have sent them. Almost everything below follows from that one sentence.
1. What Bosun is for
Replying to people who wrote to you first.
Every recipient of a message sent through Bosun exists in your account because they emailed your support address. The product has no mechanism to send to an address that has not written in: there is no list to import, no contacts to upload, no way to compose to an arbitrary recipient, and no bulk send.
2. What you must not do
Send unsolicited mail. No marketing campaigns, newsletters, promotions or outreach of any kind, whether or not the recipient once wrote to you. Bosun is not a sending platform and must not be used as one.
Send to addresses you did not obtain by being written to. Including addresses bought, scraped, harvested, guessed, or exported from another system.
Send on behalf of anyone but yourself. Your account sends from a domain you control and have verified. Do not use it to send for a third party, resell access, or operate it as a mail relay.
Send unlawful, fraudulent or harmful content. Including phishing, impersonation of another person or organisation, malware, and anything unlawful in the United Kingdom.
Evade our controls. Including creating a second account after a suspension, splitting sending across accounts to stay under a threshold, or attempting to disable, bypass or interfere with the suppression list.
Interfere with the service. Including probing, scanning or load-testing our infrastructure without written permission, attempting to access another customer's data, or automating the interface in a way that degrades it for others.
3. Your responsibilities
You are the data controller for the mail in your inbox. You are responsible for having a lawful basis for what you do with it, for what your team members do with your account, and for keeping their credentials secure.
You must tell us promptly if you believe an account has been compromised: hello@usebosun.com.
4. What we enforce, and how
These are controls in the product, not intentions.
You cannot send until you prove you own the domain. Sending is blocked in the interface until you publish DKIM records for your own domain and we verify them. An abuser would have to control the DNS of the domain they want to send as, which is the same bar their own mail provider sets.
Complaints and hard bounces suppress the address. A complaint or a hard bounce adds that recipient to a suppression list scoped to your account. The suppression is checked in our own code before a send reaches our mail provider, so a suppressed address cannot be contacted again through Bosun even if you try.
We suspend sending automatically at a bounce or complaint rate. Over a rolling window of 1,000 messages, and once at least 25 have been sent:
| Bounce rate | Complaint rate | |
|---|---|---|
| Paid accounts | 5% | 0.1% |
| Trial accounts | 3% | 0.05% |
Crossing either suspends your sending pending human review. This is automatic and is not a judgement about you — it protects the sending reputation every customer on the platform shares.
Receiving is never suspended. Not for exceeding a threshold, not for non-payment, not during a review. Whatever else happens, mail addressed to you continues to arrive and nothing is deleted. Your correspondents must never receive a bounce because of a dispute between us.
Mail carrying a virus is quarantined on arrival rather than shown.
5. If you breach this policy
Depending on what has happened, we may suspend sending, suspend the account, or terminate it. We will tell you what we found and what we did.
For anything short of deliberate abuse we will contact you first. A run of bounces is usually one bad address list pasted into a thread, not bad faith, and it is our job to know the difference.
Where an account is terminated for breach, your data remains available for export for the retention period set out in the Privacy Policy. We do not hold data hostage.
6. Reporting abuse
If you have received mail sent through Bosun that breaches this policy, tell us at hello@usebosun.com with the full message headers. We investigate every report and will tell you the outcome.
7. Changes
We will post changes here and notify account owners by email at least 30 days before they take effect, unless a change is needed sooner to address abuse or to comply with the law.
VECTOR AND WING LIMITED, trading as Bosun · 82a James Carter Road, Mildenhall, IP28 7DE, United Kingdom · hello@usebosun.com