GroupWise problems

[Chris Sampson]

We have a client who are using GW 5.5, and she is having these
problems.

1) When she sends out an appointment to everyone, not everyone gets
it, and out of those who do get it, most get it as an email not an
appointment.

2) Cannot perform a 'busy' search to see if people are available. She
gets a:
"User.POFF...@company-name.com" is undeliverable for BUSY
SEARCH: "User.POFF...@company-name.com".GWIA.DOMAIN"
mail back.

3) When she sends appointments, sometimes she doesn't get a
notification that it has been delivered, even though it is set to do
so by default.

Any ideas would be appreciated.
Thanks.