You treated it correctly by logging in to the Auctiva site directly without using any of the links on it.
Same goes for any suspicious mails of this type.
However if it had any images within it that were from the actual senders site then the email reader tool would fetch those to display them and would confirm to the actual sender your email address is a live one so expect somewhat more in the near future.
Sounds like a standard phishing mail just like those I get allegedly from eBay or PayPal on a regular basis asking to confirm my details with threats of account closure etc if I don't, those I forward to spoof@ebay or spoof@paypal.
Certainly do not reply to it and add the sender to your junk mail list, you could paste it into a file support request not that Auctiva can probably do anything about it.
The real senders address will be disguised as Auctiva but the block will apply to the real sender.
Best not to auto-delete junk mail, they are not infallible
edit - the junk mail filters that is