I moved the registration of my domain mbvelden.net from DreamHost, where it is currently hosted, to TransIP.nl, where over time I intend to run everything I need from a VPS. I want to keep the DreamHost hosting intact for at least a few more months. Mainly because they also host my mail.
The move was complete within a few hours with only a few confirmation emails to handle. Unfortunately I did not think to check the DNS records until I found that I could not connect to the mail server any more with Thunderbird. When I did check I found that mbvelden.net was pointing at a placeholder site and the mail MX records were pointing nowhere.
Luckily the DreamHost panel still showed their last version of the DNS records and I copied these values to the DNS records at TransIP. After a few hours everything started to work again. Now I am just not sure how many emails I have missed in the process. Oh well, if it is important I will hear about it anyway.