Does SmtpFailedRecipientsException ever occur?

[GoogleNewsReaderMan]

I can't seem to ever get this exception when sending to a bogus
address.
Can anyone else?
Does the SMTP server need to implement a particular protocol version
for this to work?
I thought mail was sent to an SMTP server and it could be queued there
for a while, and so information like this would not be known.
Thanks for the help!

 

[Danny Tuppeny]

I can't seem to ever get this exception when sending to a bogus
address.
Can anyone else?
Does the SMTP server need to implement a particular protocol version
for this to work?
I thought mail was sent to an SMTP server and it could be queued there
for a while, and so information like this would not be known.
Thanks for the help!

What about if you're connecting directly to the SMTP server that handles
mail for the recipients domain?

 

[GoogleNewsReaderMan]

I don't know.
Is that how it is supposed to work?
The only time I would connect to the recipient's SMTP server is when it
happens to be the same as mine!
What's the story? How is this supposed to work?
Does anybody have an answer?
Thanks again for any help!

 

[Danny Tuppeny]

I don't know.
Is that how it is supposed to work?

I've no idea

There may be a few reasons why you'd connect directly to the recipients
mailserver though. For one, you might be delivering locally (to people
with mailboxes on your server). You may also be writing an application
that sends email by directly connecting to the recipients mailserver
(like many bulk email apps do) so messages like "mailbox full" can be
caught at that time, rather than being bounced as emails potentially
hours later!

Looking at the docs,

http://msdn2.microsoft.com/en-us/library/system.net.mail.smtpfailedrecipientsexception.aspx

I'd say the above is true. If you connect directly to the mailserver,
and the mailbox is busy/unavailable etc., this exception is thrown
(that's assuming the MS example works )