[Info-vax] bizarre SMTP problem

[sapienzaf]

On Apr 9, 4:17 pm, "Bob Eager" <rd... at spamcop.net> wrote:
> Then it appears to be a bug, since '+' is perfectly valid as a character
> in an email address, as per RFC 2822 section 3.4.1.
>

Uh, no, sorry that's wrong.  A bit too eager to jump on that without
understanding the context.

The response to a "To:" prompt from OpenVMS Mail is subject to the DCL
parsing rules, and a '+' delimits parameters on an input line.  The
way to get the '+' interpreted as part of an SMTP mail address is by
enclosing it in double quotes and preceding it by the SMTP%  prefix
(which the OP apparently figured out).

In this context, the '+' outside of double quotes is ambigous.  For
example:

MAIL> SEND
To: frank+bob at eager.com
...

Is this a request to send the message to two recipients ("frank", a
local OpenVMS user and "bob at eager.com" being an SMTP recipient) or a
request to send a message to one recipient ("frank+bob at eager.com"
being an SMTP address)?

The error message being reported by Mail makes it clear that Mail is
seeing it as two recipients.  That's the way we should expect it.