Every mail service limits how fast and how much each mailbox can send. Domain India Business Email does too, and for a good reason: all customers' mail leaves from the same mail servers, so one hacked mailbox sending spam could get everyone's mail refused by Gmail and Outlook. This guide explains the limits, how they are counted, what a refusal looks like and what to do if you need to send more.
Each mailbox can send in bursts of up to 30 messages a minute, 500 an hour and 2,000 a day on the standard tier. A single connection from a mail app or script can carry 10 messages, then it must reconnect. A limit shows as a temporary 452 error, and well-behaved mail apps retry on their own. Business Email is for correspondence, not newsletters. If a limit blocks genuine business mail, open a ticket.
1. The standard limits
| Window | Standard limit per mailbox |
|---|---|
| Per minute (burst) | 30 messages |
| Per hour | 500 |
| Per day | 2,000 |
| Per connection | 10 messages, then reconnect |
Every mailbox starts on these limits. They are set well above what one person writes in a working day, so most people never meet them. The daily figure is a total for the day, not a rate: you can't send 500 every hour for 24 hours.
A higher tier exists for customers with a genuine, sustained need. You can't switch it on yourself. Open a ticket from your account, say what you send and why, and support will look at it with you.
These are the limits on Business Email at the time of writing. They protect every customer's delivery, so they may be adjusted. If a figure here doesn't match what you see, open a ticket and we will check your mailbox.
2. Webmail and mail apps are counted differently
This is the part that confuses people, because it explains results that look inconsistent.
- Sending through webmail counts recipients. One message to 60 people counts as 60.
- Sending through a mail app (Outlook, Apple Mail, Thunderbird, a phone, a script) counts messages. One message to 60 people counts as one message.
So the same announcement can use very different amounts of your allowance depending on where you send it from. If you are close to a limit and getting mixed results, this is almost always the reason.
3. The 10-messages-per-connection cap
Separately from the hourly and daily limits, one connection to the mail server can carry at most 10 messages. A program that opens one connection and pushes hundreds of messages down it is refused after the tenth, even when you are nowhere near your hourly limit.
Ordinary mail apps reconnect on their own, so you won't notice. It matters when you send from a script, a website or an application: have it close the connection and open a new one every few messages.
4. What a refusal looks like
Both kinds of limit refuse with a 452 code, but the wording differs. Read the message, not only the number.
| Message from the server | What it means | What to do |
|---|---|---|
452 ... Maximum number of messages per session exceeded | The 10-per-connection cap | Reconnect and carry on |
452 ... Rate limit exceeded, try again later | A per-minute, hourly or daily limit | Wait, then send the rest |
A 452 is a temporary refusal, not a permanent failure. Mail apps usually keep the message in the Outbox and retry automatically, so often you don't need to do anything. Nothing is lost.
5. Why the limits exist
Business Email's mail servers are shared, and so is their reputation with Gmail, Outlook and every other provider. If one mailbox is taken over and starts sending spam, providers start refusing mail from those servers, and every customer's mail suffers, not just the spammer's.
Sending limits cap the damage a stolen password can do before it is noticed. They are one reason to use app passwords and two-factor authentication: a password that is never stolen can't be abused.
6. Don't send bulk mail or newsletters from a mailbox
Please don't use Business Email for newsletters, promotions or large mailing lists. It isn't a smaller version of the right product; it is the wrong product.
A mailbox is built for correspondence. Marketing mail needs unsubscribe handling, bounce processing, list cleaning and reputation management that a mailbox doesn't provide. Sending a campaign from your mailbox also risks your domain's reputation, and that affects your everyday business mail: quotes, invoices and replies to customers that you can't afford to have filtered as spam.
For campaigns, use a dedicated email marketing service. When you do, add it to your domain's SPF record. A domain may have only one SPF record, so add the service to your existing record rather than creating a second one. Understanding SPF shows how to combine them.
7. Staying under the limits
If your mailbox suddenly hits limits you have never hit before, and you didn't send the mail yourself, treat it as a possible compromise. Reset the mailbox password from the client area, revoke unused app passwords, and open a ticket.
8. Where Domain India Business Email fits
Business Email is a dedicated mail service for day-to-day business correspondence at your own domain, with DKIM signing on every message and SPF and DMARC records supplied for your domain in the client area. It is priced per mailbox, starting from one; the card shows the live price, excluding 18% GST.
- Priced per mailbox - start with one
- Email at your own domain ([email protected])
- Add and remove mailboxes yourself
- Webmail with calendar, contacts and tasks
Frequently asked questions
How many emails can I send per day with Domain India Business Email?
On the standard tier, each mailbox can send up to 2,000 messages a day, 500 an hour, and 30 a minute in bursts. A single connection can carry 10 messages before it must reconnect.
Why does webmail count my message to 50 people as 50?
Webmail counts recipients, while a mail app such as Outlook counts messages. One message to 50 people is 50 against your webmail allowance but one message from a mail app.
What does "452 Rate limit exceeded, try again later" mean?
Your mailbox reached one of its sending limits. It is a temporary refusal: wait and send again, or let your mail app retry automatically. Nothing is lost.
What does "452 Maximum number of messages per session exceeded" mean?
Your app or script sent 10 messages over one connection. Have it disconnect and reconnect; ordinary mail apps do this on their own.
Can I get a higher sending limit?
A higher tier exists for customers with a genuine, sustained need, and it can't be switched on yourself. Open a support ticket from your account explaining what you send and why.
Can I send newsletters from Business Email?
No. Mailboxes are for correspondence. Use an email marketing service for newsletters and campaigns, and add it to your existing SPF record, because a domain may have only one SPF record.
Ready to send? Check your mail app settings, make sure your DNS records are published so your mail is trusted, and open a support ticket if a limit is blocking genuine business mail.
Tell us your domain, the mailbox, and what you are sending, and we will look at your limits with you.
Talk to our support team