Rename mail configuration files

diff --git a/mail/.mutt/mutt.uk.ac.aber.maf54_offline b/mail/.mutt/mutt.maf54@aber.ac.uk_offline
similarity index 100%
rename from mail/.mutt/mutt.uk.ac.aber.maf54_offline
rename to mail/.mutt/mutt.maf54@aber.ac.uk_offline

diff --git a/mail/.mutt/mutt.uk.ac.aber.maf54_online b/mail/.mutt/mutt.maf54@aber.ac.uk_online
similarity index 100%
rename from mail/.mutt/mutt.uk.ac.aber.maf54_online
rename to mail/.mutt/mutt.maf54@aber.ac.uk_online

diff --git a/mail/.mutt/mutt.com.friedersdorff.com b/mail/.mutt/mutt.max@friedersdorff.com
similarity index 100%
rename from mail/.mutt/mutt.com.friedersdorff.com
rename to mail/.mutt/mutt.max@friedersdorff.com