This is a spam email. There is not so much special about, just the recipient address. “Single use” email addresses have an advantage of trackability of spam sources, because once you start receiving messages onto this alias you immediately know the source. Not to say that you can block them easily.
Google Mail offers a similarly useful option of an optional suffix on the email address which is automatically stripped on message delivery:
firstname.lastname@example.org is delivered to
email@example.com and one can add
bars to help oneself sorting and tracking messages.
I am not the one receiving spam onto registration email with dlinkddns.com: dlinkddns email details leaked?.
Bonus reading: Use of the “+” to track email abuse: Using gmail filters.