[DUG] Problems with TDSMTP

[Alister Christie]

> Interesting that your clients subscribers are coming up with email addresses
> that don't exist ;)

Many of the email addresses are given via word of mouth so this is not 
supprising at all, and accounts can disappear over time (people changing 
ISPs or moving country etc).

> Also interesting that hiding the error 550 rather than
> reporting it is what a valid newslist would want. Surely they'd like to know
> that their valid customers address is wrong ;)
> 
> Also. 550 is a generic error, used for more than one thing by the ISP. You
> need to contact them. It's got nothing to do with the indy code.

My problem is not the 550 response as such, I was handling these fine 
under Indy 9 (reporting which email addresses were invalid).  Now that 
I've upgraded to Indy 10 blank emails go out to each email address upto 
the one that gave the 550 response, which is highly undesirable.

> For example. In NZ SMTP rerouting is not possible. Explained: if you are an
> xtra user, and you take your laptop to a house that uses orcon, you cannot
> send mail using smtp.xtra.co.nz at that line. You must use smtp.orcon.net
> even though you are an xtra customer. And vise versa. It's a telecom trick
> so that they can charge extra for their SSL enabled smtp servers. This will
> also return you a 550 error.

If you supply your username and password to the SMTP server, you can 
send an email via an ISP that is different to it's corresponding smtp 
server.  For instance this email was sent via smtp.ihug.co.nz, however 
I'm currently using an xtra jetstream connection.  I find this very 
handy as I take my laptop onsite, and it's nice to be able to just plug 
in and send emails.

Alister