Change RBL presence in Spamblocker exim.conf

At the moment, these are the RBL's in spamblocker exim.conf:
[/code] cbl.abuseat.org :
bl.spamcop.net :
combined.rbl.msrbl.net :
b.barracudacentral.org :
zen.spamhaus.org :
hostkarma.junkemailfilter.com=127.0.0.2[/code]

If we don't want one of them in there, we can exclude them by editting the exim.strings.conf.custom file.

However, imho it's better to have the users choose if they want the less known RBL's in there, so turn it around, leave them out there and let the users decide.

Abuseat, Spamcop and spamhaus are the most known and should be present maybe also the msrbl.net, I'm not sure.
Hostkarma however, does not do much and the only time I've seen them blocking something it were false positives.

Then barracudacentral. It's great but...:

They might not do that, but it's at least decent to forfill their request for making use of their list, unless DA has a special deal with them to set up barracuda in Exim by default.

So my request is to only have Abuseat, Spamcop, Spamhaus and maybe combined.rbl.msrbl.net in Exim.conf by default, and remove the others, let the users decide about what they want added. So rather an opt in than an opt-out like it's now.

And remove that hostkarma false positive thing.