Downtime due to network infrastructure maintenance

To keep up with our growing sending volume, we are going to make some changes to our network infrastructure in the coming weeks in cooperation with our hosting providers. In the process, the IP addresses used for sending email will be routed differently so that they can be used more flexibly and with greater capacity.

Wednesday, 11 October 2023 at 20:00 (CET) no email will be sent temporarily from the affected IP addresses. Messages scheduled during this period will be queued and delivered with a delay after the work is completed. Therefore, no e-mail will be lost, and the API's and user interface of the software will also remain accessible during the operation. However, the delay can be as long as an hour in the worst-case scenario.

Why is it taking so long?

While the work is not that complex in principle, it involves multiple companies, multiple people and multiple systems. To be on the safe side, we therefore stop outgoing traffic, and communicate a generous maintenance window of one hour on the advice of our supplier.

Can we switch to a different IP address?

When moving web servers or other servers, DNS normally allows switching between systems without downtime. This is a bit trickier for e-mail, because for outgoing e-mail, IP addresses are more valuable than for web traffic, for example.

IP addresses used for e-mail traffic have a sending reputation. Mail coming from "good" IP addresses is less likely to be blocked or placed in the spam folder than mail from "bad" or "unknown" IP addresses. This is why we always use the same IP addresses for each customer for outgoing mail traffic. For this reason, we do not recommend sending mail from a different IP address from one moment to the next.

In addition, we are going to route a very large group of IP addresses differently. We do not have enough alternative addresses at our disposal to temporarily link all accounts to other addresses without these accounts getting in each other's way. Therefore, our advice is to accept the possible delay, and not to temporarily switch to a different IP address.

Is there an alternative?

However, it is possible to temporarily use a different IP address. If continuity and speed of email is important, we can link accounts to another IP address shortly before the work begins. After completion of the work, the account will be reset to the original IP address. Mails are then sent immediately, but with a new IP address so that messages may not be delivered to the inbox.

If you would like to make use of this arrangement, please contact our support department on time at