Daily email limit reached

This article provides some additional information.

If you have reached this limit, it means that you have indeed sent so many emails yourself that you have exceeded the limit, or that your account is being misused by third parties to send spam. It is mainly for this last reason that we do not set the default limit per account too high. Should your account unfortunately be hacked and misused to send spam, the amount sent can never exceed the daily limit. In that case, please contact us as soon as possible.

The message you may get once you have exceeded your limit is:
This message was created automatically by mail delivery software.

A message that you sent could not be delivered to one or more of its
recipients. This is a permanent error. The following address(es) failed:
voorbeeld@domein.xx
Unrouteable address