Our outgoing mail servers are shared by all our customers: if one of them sends thousands of messages in a short time, everyone's reputation suffers, and Gmail, Outlook and other providers start rejecting everyone's email or filing it as spam. This is why the number of emails sent per hour is limited. This article explains what happens when the limit is reached, and how to organise a mailing to a large number of recipients.
In short: the limit is 1000 emails per hour; beyond it, messages are not lost but delayed. For many recipients, use a mailing list (E-mail card, Mailing lists), limited to 200 messages per hour.
Requirements
- Email hosted at SwissCenter: the E-mail card appears in the Hosting management of your domain.
Good to know before you start
- The limit is 1000 emails per hour. It is not shown in the Apanel console. Beyond it, messages are not lost, but their sending is delayed.
- Once the limit is reached, the next messages do not leave straight away: our outgoing servers refuse them temporarily, and they are submitted again later. Their delivery is therefore delayed. A message that still cannot be sent ends up coming back to you with a non-delivery report.
- An abnormal sending volume is often a sign of a hack: a mailbox whose password has been found out, or a contact form abused by bots. Our team may then block the mailbox or the sending from the website concerned.
How do I write to many recipients?
To write regularly to the same people (members, customers, an association's members), use a mailing list rather than putting hundreds of addresses in copy: you send a single message to the list address, and the server forwards it to each subscriber.
- Log in to your Apanel console.
- From the dashboard, click your domain name to open Hosting management.
- In the E-mail card, click Mailing lists, then Add mailing list.
The Mailing lists button only appears if your email is hosted on our SmarterMail mail server. Creating and managing a list is described in Creating and managing a mailing list.
A mailing list has its own limit:
- A list created from the Apanel console sends at most 200 messages per hour. Beyond that, the mail server delays the next messages until the rate drops back under this limit. A mailing to a large number of subscribers can therefore be spread over several hours: plan for it when an announcement must arrive by a given date.
- Messages distributed by a list of your domain, when you write to the list from an address of that same domain hosted with us, are not subject to the hourly limit of our outgoing servers: the list's own limit regulates them.
For marketing campaigns to a very large number of recipients (newsletters, promotions), a specialised email marketing service remains the best fit: it handles unsubscriptions, invalid addresses and open statistics.
Troubleshooting
| What you see |
What to do |
| A delay or non-delivery report that mentions a sending rate limit ("rate limit") |
The hourly sending limit has been reached. Wait before sending new messages, spread your sending over time, or use a mailing list. |
| Messages leave your mailbox without you having sent them |
The mailbox password has probably been found out. Change it straight away: see Unblock a mailbox blocked after sending spam. |
| Your mailbox can no longer send, and our support team has told you it was blocked |
Follow the steps in Unblock a mailbox blocked after sending spam. |
| Messages from your mailing list arrive several hours late |
This is the effect of the list's limit of 200 messages per hour. Send your announcements early enough. |
Going further