"Blocked Addresses" list not working

[#1]

I've been getting increasing amounts of "betting" emails. Admittedly most of them end up in my Spam box but it's tedious deleting them. So at the weekend I added several addresses to my Blocked Addresses listing when several emails were coming from the same address - see screenshot 1. However lots are still getting through - both yesterday and today - refer screenshot 2. I've checked the headers and as far as I can tell the sending email is the one I've copied out.
So is the relevant component faulty or what's the explanation otherwise?
Ideas please!

[#2]

Have you checked the actual send address as opposed to a possibly fiddled one

[#3]

Yes - as far as I can tell. I'll try looking again in more detail.

[#4]

If there is a different reply-to address in the headers try adding that to the blocked list.

[#5]

Here's a typical header with my info removed:

Return-path: <returns@a.ss51.mailboxesmore.com>
Envelope-to: [my plusnet address]
Delivery-date: Tue, 18 Mar 2014 16:33:50 +0000
Received: from [212.159.9.108] (helo=avasin08.plus.net)
    by inmx20.plus.net with esmtp (PlusNet MXCore v2.00) id 1WPwxa-0007eD-0N
    for [my plusnet address]; Tue, 18 Mar 2014 16:33:50 +0000
Received: from mailex.mailcore.me ([94.136.40.141])
    by avasin08.plus.net with Plusnet Cloudmark Gateway
    id f4Zn1n00732k5W6014ZpAV; Tue, 18 Mar 2014 16:33:49 +0000
X-BV-Spam-Flag: Yes
X-IPAS: Level1
X-CM-Score: 100.00
X-CNFS-Analysis: v=2.1 cv=fN633Pqe c=1 sm=1 tr=0 p=eH9kHV86AAAA:8
    a=bheWAUFm1xGnSTQFbH9Kqg==:117 a=bheWAUFm1xGnSTQFbH9Kqg==:17 a=0Bzu9jTXAAAA:8
    a=SiPxQWYhlA4A:10 a=3u-1L5pIEcoA:10 a=3oc9M9_CAAAA:8 a=KeETP6AxAAAA:8
    a=hGuNbvm7AAAA:8 a=mSoEbbAok8uzzrSYVk8A:9 a=QEXdDO2ut3YA:10 a=11_FmqaVCJEA:10
    a=S2d2uCKir3QA:10 a=q4QnpWDoIFgA:10 a=ElIQyAiaR9AA:10 a=1IC0RHT2vVMA:10
    a=1by5bfFQvSsA:10 a=344U6QoxAAAA:8 a=Qh7kmIokAAAA:8 a=dy2-BLufGHNgPqBPCUgA:9
    a=9_h89MdkE9zyC5Qf:21 a=FLF5c3xWch5bdnVf:21 a=qiNsjFG1kqGe9LnZ:21
    a=frz4AuCg-hUA:10 a=tXsnliwV7b4A:10 a=gDU99AyPswQA:10 a=9mtKWAJ7pHgA:10
    a=jy4nPlRYKq0A:10 a=4FZ7CBgTfG0A:10 a=747UUNwWIyIA:10 a=U8Ie8EnqySEA:10
Received: from a.ss51.mailboxesmore.com ([66.18.14.210])
    by smtp03.mailcore.me with esmtp (Exim 4.80.1)
    (envelope-from <returns@a.ss51.mailboxesmore.com>)
    id 1WPwxW-0001P6-9z
    for [my email address]; Tue, 18 Mar 2014 16:33:47 +0000
Received: by a.ss51.mailboxesmore.com (Postfix, from userid 0)
    id 6DE371287EDD; Tue, 18 Mar 2014 18:33:45 +0200 (SAST)
To: [my email address]
Message-ID: <897796-1395159705000-70707-236074248-1-0@ss51.mailboxesmore.com>
X-Track-ID: <1395160425_SectionID-897796_HitID-1395159705000_SiteID-70707_EmailID-236074248_DB-1_SID-0@ss51.mailboxesmore.com>
List-Unsubscribe: <mailto:unsub_MHw3MDcwN3wxMzk1MTU5NzA1MDAwfGRyakBkcmpvbmVzLmNvLnVr@d.ss51.mailboxesmore.com?subject=Unsubscribe%20[my email address]>,<http://is.ss51.mailboxesmore.com//RWCode/subscribe.asp?Mode=unsubscribe&SiteID=70707&SID=0&Email=[my email address]>
X-Report-Abuse: Please report abuse for this campaign here: http://is.ss51.mailboxesmore.com/reportabuse.aspx?stid=70707&hitid=1395159705000&sec=897796&email=[my email address]&EmID=236074248&SID=0&token=40fa7755bb144611c2b19159362b982dfc645c2e
DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=ss51.mailboxesmore.com; i=@ss51.mailboxesmore.com; q=dns/txt; s=gmmailerd; t=1395160341; h=From; bh=47DEQpj8HBSa+/TImW+5JCeuQeRkm5NMpJWZG3hSuFU=; l=0; b=AMtQQdFF2NzVibo4Brt+y8jhQmqkbPqMQO+1qX2LXNt599eIqE0acn8if3J3dpMrSceUzNWHWLHYbkRACC59SyS2kK9XvRL3Nsj63uKBltXMOV8XA+EC3GjZmP0UWyRXAL/5x/d60mSXZptMmQgP7jYRlQFQfet0CV9tg8kebsM=
From: "JrTips" <jr.sports@aol.com>
Mime-Version: 1.0
Content-Type: multipart/alternative;
    boundary="339e7d219181157db022ba5e349da70a"
Date: Tue, 18 Mar 2014 18:33:45 +0200 (SAST)
X-pn-pstn: Spam 1
X-PN-Virus-Filtered: by PlusNet MXCore (v5.00)
X-PN-Spam-Filtered: by PlusNet MXCore (v5.00)
Subject: [-SPAM-] Red Alert Line Error! Get info that is 6pts off- See why highroller raise their limits-B.B.C VIP Underdog will win oiutright Monitored 74% Winners

I've taken the email address from: From: "JrTips" <jr.sports@aol.com>
Perhaps I should instead be blocking returns@a.ss51.mailboxesmore.com instead - or maybe just the domain name: mailboxesmore.com ?

[#6]

I think it will be the envelope from that you will need to put in but will be the full a.ss51.mailboxesmore.com. The danger is that you could possibly be getting some genuine emails from the same location.

[#7]

Still suffering from unwanted repeat Spam - unfortunately I've realised they keep changing the "envelope from" address - so I conclude there's nothing I can do?