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.
I’ve been seeing a lot of discussion on various fora recently about increased delivery issues at Hotmail. Some senders are seeing more deferrals, some senders are seeing more mail in the bulk folder. Some senders aren’t seeing any changes.
This leads me to believe that Hotmail made some adjustments to their filtering recently. Given some senders are unaffected, this appears to be a threshold change or a calculation change, tightening up their standards. The changes have been around for long enough now it does look like the filtering is working as intended and Hotmail is not going to roll these changes back.
So what can you do to fix delivery of mail that was good enough at Hotmail a few weeks ago and now isn’t?
There are a number of sites online that provide public information about reputation of an IP address or domain name.
Read MoreISPs are continually developing tools for their users. Some of the newer tools are automatic filters that help users organize the volumes of mail they’re getting. Gmail released Priority Inbox over a year ago. Hotmail announced new filters as part of Wave 5 back in October.
All of these announcements cause much consternation in the email marketing industry. Just today there was a long discussion on the Only Influencers list about the new Hotmail filtering. There was even some discussion about why the ISPs were doing this.
I think it’s pretty simple why they’re creating new tools: users are asking for them. The core of these new filters is ISPs reacting to consumer demand. They wouldn’t put the energy into development if their users didn’t want it. And many users do and will use priority inbox or the new Hotmail filtering.
Some people are concerned that marketing email will be less effective if mail is not in the inbox.