Problems adding users - illegal chars in email

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Hi,

I've just migrated a WSS site to a brand new server. The users from the
old site were created during the migration, and worked successfully.

However when I try to add brand new users via Sharepoint, when I get to
the step where the passwords/welcome message are meant to be sent I get
an error:

"The E-Mail address '<some email>' contains illegal characters."

This happens *regardless* of the actual email address. Even ones with
nothing controversial whatsoever, just alpha chars, the @ symbol and a
fullstop.

If I select the option to send the welcome email, but NOT the password
email, then the user is created successfully, but the welcome message
never arrives, and I get the following error:

"The user or users have been added successfully, but there was an error
in sending the e-mail message. The server may not be set up correctly
to send e-mail. To verify that e-mail is configured correctly, contact
your server administrator."

However I know the SMTP server is set up correctly, since alerts work
OK for existing users. And also when the site was migrated, although
the user accounts were created in AD we still had to manually add them
to the Sharepoint site, and the welcome emails for those were sent
successfully.

Please help, even if you only have an inkling of what it might be, at
least it might point me in the right direction. I can't find anything
in the documentation, on the web, or in the newsgroups referencing this
error.

Thanks
Tom Walter

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