diff --git a/extras/sponge.rb b/extras/sponge.rb
index a099e9b7..98aaed51 100644
--- a/extras/sponge.rb
+++ b/extras/sponge.rb
@@ -3,6 +3,10 @@ require "net/https"
 require "resolv"
 require "ipaddr"
 
+class BadIPsError < StandardError; end
+class DNSError < StandardError; end
+class NoIPsError < StandardError; end
+
 module Net
   class HTTP
     attr_accessor :address, :custom_conn_address, :skip_close
@@ -111,7 +115,7 @@ class Sponge
         ips = Resolv.getaddresses(uri.host)
 
         if !ips.any?
-          raise
+          raise NoIPsError
         end
 
         # reject ipv6 addresses
@@ -123,21 +127,21 @@ class Sponge
       end
     rescue Timeout::Error => e
       if retried
-        raise "couldn't resolve #{uri.host} (DNS timeout)"
+        raise DNSError.new("couldn't resolve #{uri.host} (DNS timeout)")
       else
         retried = true
         retry
       end
     rescue => e
-      raise "couldn't resolve #{uri.host} (#{e.inspect})"
+      raise DNSError.new("couldn't resolve #{uri.host} (#{e.inspect})")
     end
 
     if !ip
-      raise "couldn't resolve #{uri.host}"
+      raise DNSError.new("couldn't resolve #{uri.host}")
     end
 
     if BAD_NETS.select {|n| IPAddr.new(n).include?(ip) }.any?
-      raise "refusing to talk to IP #{ip}"
+      raise BadIPsError.new("refusing to talk to IP #{ip}")
     end
 
     host = Net::HTTP.new(ip.to_s, uri.port)
diff --git a/script/send_new_webmentions b/script/send_new_webmentions
index 94a3726e..2de61c00 100755
--- a/script/send_new_webmentions
+++ b/script/send_new_webmentions
@@ -78,9 +78,14 @@ if __FILE__ == $PROGRAM_NAME
 
     sp = Sponge.new
     sp.timeout = 10
-    response = sp.fetch(WEBrick::HTTPUtils.escape(s.url), :get, nil, nil, {
-      "User-agent" => "#{Rails.application.domain} webmention endpoint lookup",
-    }, 3)
+    begin
+      response = sp.fetch(WEBrick::HTTPUtils.escape(s.url), :get, nil, nil, {
+        "User-agent" => "#{Rails.application.domain} webmention endpoint lookup",
+      }, 3)
+    rescue NoIPsError, DNSError
+      # other people's DNS issues (usually transient); just skip the webmention
+      next
+    end
     next unless response
 
     wm_endpoint_raw = endpoint_from_headers(response['link']) ||