KT8 Mail and your Cloudflare bill.
KT8 Mail runs in your own Cloudflare account, so Cloudflare bills you directly for what it uses. Most small teams stay within Cloudflare’s $5 Workers Paid plan. Busier teams can go over its limits, and Cloudflare then charges for the extra. This page shows what each plan includes, what extra use costs, and the numbers that keep you inside the plan.
Check Cloudflare’s own pricing first. Cloudflare sets these prices and limits and can change them at any time. We checked the figures on 29 October 2026. Cloudflare’s pricing pages are linked at the bottom of this page, and their figures always apply.
Free to receive. $5 a month to send.
Cloudflare’s free plan
Receiving email is free. You can try KT8 Mail, but you can’t send email to other people’s addresses on the free plan.
Workers Paid, $5 a month
Includes 3,000 sent emails a month for your whole Cloudflare account, about 100 a day, plus storage for your mail and files.
Going over
About $3.50 for every 10,000 extra emails sent, plus a little more each month as your stored mail grows.
What each Cloudflare plan includes.
KT8 Mail uses these Cloudflare services. Cloudflare bills in US dollars.
| Cloudflare service | What KT8 Mail uses it for | Free plan | Workers Paid ($5 a month) includes | Extra use costs |
|---|---|---|---|---|
| Email Routing | Receiving email | Unlimited | Unlimited | Free |
| Email Sending | Sending, auto-replies, forwarded copies and invites | Not available to outside addresses | 3,000 emails a month | $3.50 per 10,000 emails |
| Workers | The app, the API and every incoming email | 100,000 requests a day | 10 million requests a month | $3 per 10 million requests |
| Durable Objects | Each mailbox’s own store: email text, contacts, calendar and settings | 5 GB in total | 5 GB, plus generous reads, writes and running time | $2 per 10 GB a month |
| R2 storage | Attachments, Files and nightly backups | 10 GB (needs a payment card on file) | 10 GB | $1.50 per 100 GB a month |
| Workers AI | The AI reply assistant, off unless you turn it on | About 70 to 120 drafts a day | The same daily allowance | About $1 to $1.50 per 1,000 drafts |
| Logs | Error and activity logs for your app | 0.5 GB a day, then logging pauses until midnight (UTC) | 50 GB a month | $2.50 per 10 GB |
| Zero Trust | Signing in | Free for up to 50 people | Free for up to 50 people | KT8 Mail allows up to 50 people |
On the free plan Cloudflare never charges you: when a daily allowance runs out, that service stops until midnight (UTC). On Workers Paid nothing stops, and Cloudflare bills you for the extra.
Staying at $5 a month.
These figures are for your whole organisation, not for each person.
- Send up to 3,000 emails a month, about 100 a day. To be safe, count each person an email goes to as one email.
- Keep email text under 5 GB across all your mailboxes, which is roughly 125,000 typical emails.
- Keep attachments, files and backups under 10 GB. Backups count: keeping 3 nightly copies of a 3 GB mailbox uses 9 GB.
- Using the AI reply assistant? About 70 to 120 drafts a day stay free.
- Everything else, such as requests, logs and sign-ins, stays well inside the plan for a team of up to 50 people with KT8 Mail open all working day.
What a month might cost.
Estimates on Cloudflare’s Workers Paid plan, including the $5. Your own figures depend on how much you send and keep.
| Example | Sent a month | First month | After a year | What adds to it |
|---|---|---|---|---|
| 1 person, sending 30 and receiving 60 emails a day | 900 | $5 | $5 | Nothing over the plan |
| 5 people, sending 100 and receiving 300 emails a day between them | 3,000 | $5 | about $6 | Stored mail starts to add a little |
| 10 mailboxes, 3,000 emails a day (1,500 sent and 1,500 received) | 45,000 | about $20 | about $33 | Sending about $15; storage about $13 after a year |
| 10 mailboxes at KT8 Mail’s sending limit (2,000 sent and 3,000 received a day) | 60,000 | about $26 | about $48 | Sending about $20; storage about $23 after a year |
| 50 people, each sending 25 and receiving 75 emails a day | 37,500 | about $18 | about $40 | Sending about $12; storage |
How we worked these out: an average email of 100 KB, nightly backups on and keeping 3 copies, the app open 9 hours every working day, the AI assistant off and nothing deleted. Keeping 1 backup instead of 3 brings the 10-mailbox example down from about $33 to about $27 after a year.
Limits on every plan.
These come from Cloudflare or from KT8 Mail itself, and paying more doesn’t remove them.
- Outgoing email: up to 5 MB each, attachments included. KT8 Mail sends bigger files as secure download links instead.
- Incoming email: up to 25 MB each. Bigger emails are turned away.
- Up to 50 people on one email, counting to, cc and bcc together.
- KT8 Mail’s own sending limits: each mailbox can email 50 people an hour and 200 people a day. They protect your domain’s reputation.
- Cloudflare’s daily sending limit. New Cloudflare accounts start with a lower daily limit that rises as your sending record builds. Cloudflare doesn’t publish the figure, and you can ask Cloudflare to raise it.
- Up to 10 GB of email text in each mailbox. Attachments and files don’t count towards it. A mailbox receiving 300 emails a day takes about 2 years to fill it.
- On the free plan: 5 GB of email text across your whole account, and 100,000 requests a day. Someone with KT8 Mail open uses about 3 requests a minute.
- Up to 50 people can sign in, which is what Cloudflare Zero Trust includes for free.
- Forwarding: forwarding through Cloudflare needs each outside address verified, up to 200 per account. Copies that KT8 Mail sends on count as sent emails.
- Domains and aliases cost nothing on their own. KT8 Mail uses one Cloudflare routing rule per domain, so adding aliases doesn’t use up Cloudflare’s limit of 200 rules per domain.
Simple ways to stay inside the plan.
- Keep fewer nightly backups. In Settings, open Backup & export and lower Copies to keep. Each one is a full copy of the mailbox.
- Empty Spam and Bin now and then, and delete large files you no longer need.
- Let big files go as links. KT8 Mail does this for you, so one file isn’t stored twice.
- Use a newsletter service for bulk email. KT8 Mail is for everyday email, not mailing lists.
- Check Billable Usage in your Cloudflare dashboard each month, so you see any extra charges early.
KT8 never adds anything to your Cloudflare bill, and we can’t see it. Your licence is a one-off payment to us; Cloudflare’s charges go straight to Cloudflare.
Check Cloudflare’s own pages.
Cloudflare’s prices and limits always apply, and can change. Read them before you rely on the figures above.
- Workers pricing
- Email Service pricing
- Email Service limits
- Durable Objects pricing
- R2 pricing
- Workers AI pricing
- Observability (logs) pricing
- Zero Trust plans
See also our terms, KT8 Mail pricing and why we build on Cloudflare.