Below are known issues that may be affecting some Groups users:

Hotmail Update: Good News & Bad News (current forecast: scattered showers)

The Good News

Hotmail used to reject some messages sent from Yahoo! Groups because they
exceeded 15 "hops" (the default limit set on Exchange Server to prevent mail
loops, which Hotmail refused to reset to a higher, more appropriate level:
http://kb.iu.edu/data/beha.html?osecat=email). This would happen most often in
groups that moderate messages, since the moderation process causes more hops
within our system.

But we've recently made changes to the way hops information is presented in
Yahoo! Groups headers, so that this 15 hops limit should no longer be an issue.
These changes should mean far fewer bounced messages to Hotmail members.

The Bad News:

In the last couple of weeks Hotmail has adjusted their filters in a way that is
pretty much blocking all "invitations" sent from Yahoo! Groups. And despite our
attempts to get them to stop this blocking, we’ve not yet seen them lift this
block:

So we have two recommendations:

1. If you’re sending invitations to Hotmail users through the Yahoo! Groups
system, consider also sending them a direct email (from your own email) either
pointing them to the group home page and directing them to click the “join”
button or point them directly to the join page:
http://groups.yahoo.com/group/NAME_OF_YOUR_GROUP/sjoin

2. Encourage your Hotmail users to complain to Hotmail about the problem.
Ultimately, they will only take action to fix the problem if enough Hotmail
users complain.

Calendar Reminders (current forecast: clear skies ahead)

We’ve recently seen a surge in reports of calendar reminder problems affecting
approximately 20% of our users. The Calendar team pushed a fix on Tuesday that
should have corrected this issue. Let us know if you are still experiencing this
issue by commenting below or submitting a report to Customer Care:
http://help.yahoo.com/l/us/yahoo/groups/original/forms_index.html

One thing to be aware of is that if someone posts an event to the calendar who
is on moderation status, a reminder won’t be sent.

Thank you,

Jami Heldt
Groups Community Manager