[imp] Invalid response code from server & 554 sorry, your envelope sender is in my badmailfrom list (#5.7.1)

[John McKinney]

I have an email problem. I just purchased a Treo 650 (Cingular) to allow for
web and email access on the go. After setting up VersaMail to check email I
can no longer send email from my laptop or the Treo. I can receive the mail
fine but when I try to create a new email or respond to a received mail I
get the following error message:

554 sorry, your envelope sender is in my badmailfrom list (#5.7.1)

When I log into the Horde site to for mail access again I can receive the
mail but when I try to send, or reply, I get the following error message:

There was an error sending your message: unable to add recipient
[example at example.org]: Invalid response code received from server 

I contacted Anilta (that handles our account and they did something to fix
it. But, the first time I checked the email for the Treo everything stopped
again. I set up an additional email account with Johnm@ instead of John@ and
it works but I need the John@ email address.

What could be the problem? Apparently this type of email can work on two
devises at a time (i.e Johnm@) but there must be a setting wrong on the
John@ account. Anilta doesn't seem to know what the issue is so I am turning
to you for advise.

John