[quote user="jbrowne"]
Two questions regarding delivery confirmation:
a) Would allowing delivery confirmations to be returned to senders, am I saying 'yes' to receiving more spam?
[/quote]
No, but it probably is saying "Yes!" to the generation of more spam; unfortunately, though your autoresponder may be harmless, some people will find it annoying if they receive it unsolicited and will accordingly often report it as spam. I should think carefully about whether or not you really need an autoresponder. See this:
http://www.spamcop.net/fom-serve/cache/329.html
Mail is dead easy to forge. A spammer just includes your autoresponder in his list and forges the sender to be some unfortunate somewhere and your helpful autoresponder will be sent to someone with no connection to your company.
The default (I.E. usual) behaviour of an RFC821-compliant mailer is only to report delivery failures. If you don't accept mail for which you can't then accept responsibility (this is configurable in Mercury), you should have no reason for generating mail to innocent people. Also, enabling Delivery Confirmation by itself isn't enough to cause a receipt to be generated; Mercury looks for a header to be present and mails the confirmation to the address in that header. There is a more standard way to change conventional SMTP behaviour using the DSN extension and format - see RFC 891. Mercury doesn't support that. Delivery confirmation will only be generated on request, in any event. So even if enabled, spammers have to knowingly abuse the feature, and most don't - yet. I don't advise you to go ahead and provide an easy way for spammers to make you generate backscatter.
[quote user="jbrowne"]
b) How possible would it be to use filters, daemons, to have automatic delivery confirmations sent back to people that email my company (even when they do not use the delivery confirmation option in their email client)?
And maybe have like an opt-in opt-out for those automatic delivery confirmations? (list of sender's email addresses that request them).
[/quote]
Yes, it should all be entirely possible using just rules and distribution lists.
Cheers,
Sabahattin