This is the second topic for this subject. The first topic received no response back from the original posters so we don't know what mail servers iceland use to send out these verification codes.
Have you contacted Iceland to ask them to check that these verification codes are being sent.
My belief is that the mail domain in use is normally icelandmail.co.uk and if this is still the case then I can see no obvious reason for mail not to be received. Have you checked your Spam folder? The DMARC policy for mail that doesn't pass authentication checks is to quarantine and this would mean the mail ends up in the Spam folder.
