I have been having the same issue since last Thursday. Logged a call with our ISP(RM) but still waiting on an official answer/call from an actual engineer!
I have therefore done a bit of investigation as I am still able to get email through to a Hotmail account, this is showing me the complete email headers. Here is what I have found:
RM are the owners of 213.18.248.93 & 213.18.248.94.
The addresses are assigned to the following mail servers:
Received: from mq3.ifl.net ([213.18.248.93]) by COL0-MC1-F20.Col0.hotmail.com
Received: from mq4.ifl.net ([213.18.248.94]) by COL0-MC1-F7.Col0.hotmail.com
mq3.ifl.net however resolves to 213.18.248.124 and mq4.ifl.net resolves to 213.18.248.119.
The reverse dns on 213.18.248.124/213.18.248.119 are correct and point to mq3.ifl.net/mq4.ifl.net respectively.
Up until 1 hour ago there was no reverse dns for 213.18.248.93/213.18.248.94. There is now a reverse dns entry for 213.18.248.93 which points to mq3.ifl.net. 213.18.248.94 still has no entry at this time.
Interestingly, on an email from last week the headers show Hotmail received RM email from 213.18.248.123:
"Received: from mq4.ifl.net ([213.18.248.123]) by COL0-MC2-F28.Col0.hotmail.com"
The reverse DNS for 213.18.248.123 is out.mq4.ifl.net.
It looks like RM have been playing around with IP address and haven't sorted out the reverse DNS entries correctly. Their site is showing that they experienced a DOS attack last week. Maybe this is the reason?
Hope this helps.
If I get a useful update I will let you know.
