So, today I found out that outbound mail from my jaapwesselius.com did not have a DKIM signature (after mail was blocked by prodigy.net). I have my jaapwesselius.com running on WordPress.com. To do this, WordPress requires to have DNS hosted with them. No problem, but adding a DKIM record in WordPress DNS is not possible, it fails with a TXT records may not exceed 255 characters error message as shown below:
The solution is relatively simple. You can add a CNAME record for the original DKIM record. For example, have safemail._domainkey.jaapwesselius.com point to something like safemailhop.exchangelabs.nl (I own that domain too, and DNS is hosted at my provider Argeweb).
CNAME: safemail._domainkey.jaapwesselius.com safemailhop.exchangelabs.nl
Create a new TXT record safemailhop.exchangelabs.nl and add the original DKIM record (from my jaapwesselius.com domain) to it et voila, that’s it.
Check with https://mxtoolbox.com/dkim.aspx reveals that it works:
And some header information:
Note. Yes I know, p=NONE in the DMARC record could (should/must) be changed to quarantine or even REJECT, but I’m still in development 😊