A number of people, both at ESPs and on the mailops mailing list, are reporting problems at Hotmail. The most common reports are senders getting
Site hotmail.com (65.55.92.152) said in
response to MAIL FROM (452 Out of memory)
during the SMTP session.
There isn’t much senders can do about this. Hotmail is going to have to fix their resource issue. This may be limited to certain mail clusters, so watching the IP addresses reporting this error and avoiding them may help.
Microsoft announced a number of changes to the Hotmail interface today. It doesn’t look like this will affect how mail is received, but will affect how users can interact with it.
As always, the best advice I can give you is send mail people want and like.
The big news in email today is Microsoft’s announcement of the next version of Hotmail: Outlook.com. This does appear to be an attempt to compete with a host of Google’s offerings. Not only does Outlook.com include Skype and access to social media accounts, but it also includes web app versions of Word, Excel and Powerpoint with 7GB of storage space.
I’m not sure how actively people will be grabbing Outlook.com addresses, as you can use hotmail.com addresses with the Outlook.com interface. Only time will tell, though, how this affects email marketing and spam filtering.
Hotmail has recently stopped using Sender ID for email authentication and switched to authenticating with SPF. The protocol differences between SenderID and SPF were subtle and most senders who were getting a pass at Hotmail were already publishing SPF records.
From an email in my inbox from September: