jamiechong

A lot of registration spam comes from emails with a subdomain. Spammers control a domain such as buymyjunk.com and then attempt to register on your site with emails such as irenemwd@foster2.buymyjunk.com and jakemgm@foster7.buymyjunk.com. This plugin simply blocks all registrations using a subdomain.
Reputable users will have a normal email address from a reasonable domain like @gmail.com, @mylegitbusiness.com, @outlook.com, @myschool.edu, etc.
There is no configuration and no setup. It simply just works. The plugin logs all blocked registrations so you can find potential false-positives. Find a link to this log file on the Plugins page where you activate/deactivate this plugin.

Ban Subdomain Emails

Prevent people from registering with emails that contain a subdomain to help reduce spam.

scribu

Whenever I visit my site’s dashboard, the first thing I see is the bold red Spam count.
Instead of wasting time deleting spam comments, I prefer to let Akismet do that automatically, so I don’t need to see how many spam comments there are.
This little plugin simply hides that part.
Links: <a href="http://scribu.net/wordpress/hide-spam-count" rel="nofollow ugc">Plugin News</a> | <a href="http://scribu.net" rel="nofollow ugc">Author’s Site</a>

Hide Spam Count

Hide the annoying spam count from the Dashboard.

Ban Subdomain Emails vs Hide Spam Count