RT's email address showing in one-time CC list

I’m in the process of moving RT 4.0.5 from an old server to a new one.
In the process, I’m also upgrading it to 4.0.23 (and maybe 4.2.x soon
after.) Its mostly going smoothly. However, in the Comment and Reply
screens of the web GUI, under “One-time Cc” and “One-time Bcc”, it
lists RT’s address at the new server.

The old server was cns.cairodurham.org (CNAME of
atlas.cairodurham.org) and the new server is its1.cairodurham.org.
Addresses like rt@cns.cairodurham.org and rt@atlas.cairodurham.org
aren’t showing in the one-time list. Addresses like
rt@its1.cairodurham.org and rt-comment@its1.cairodurham.org do show
up.

In RT_SiteConfig.pm, my RTAddressRegExp is set to:
Set($RTAddressRegexp ,
‘^{rt|help|rt-comment}@{its1.|cns.|atlas.|}cairodurham.org$’);

The script generate-rtaddressregexp suggests this:
Set($RTAddressRegexp,qr{^(?:rt(?:|-comment)@its1.cairodurham.org)$}i);

Any idea what I missed?

Thanks in advance for any help you can offer.

Jaime Kikpole
Network Administrator
Cairo-Durham Central School District

Technical Support:
help@cairodurham.org

This electronic message and any attachment(s) may contain confidential or
legally privileged information protected by law from further disclosure and
is intended only for the individual or entity identified above as the
addressee. If you are not the addressee (or the employee or agency
responsible to deliver it to the addressee), or if this message has been
addressed to you in error, you are hereby notified that you may not copy,
forward, disclose or use any part of this message or any attachment(s).
Please notify the sender immediately by return email or telephone and
permanently delete this message and attachment(s) from your system.