Do you have any experience with Exim SMTP callouts or Sendmail BMilter SMTP callbacks. I think they look promising for several reasons.
They put some of the burden on the source of the mail. They raise the bar on spoofed sender addresses. I don't think they expose the carrier to content scanning issues as the session is blocked at the headers (I could be very wrong).
SMTP callbacks can be used to verify the following:
* RFC 821, MAIL FROM:
You are required to support a NULL return path according to RFC 821. Some people disable this either because they think it's cute or because they're trying to disable spam sent with a NULL return path. Irregardless, it's broken.
* RFC 822, RCPT TO:
Sites without Postmaster accounts are simply due to admin laziness or misconfiguration. According to RFC 822, you are required to accept mail for a few specific accounts, this is one of them.
* RCPT TO:
If the sender is unknown on the machine that answers for the domain used by the sender, then either a) the site is mis-configured or b) in all probability this is a spoofed email address and the email content is spam.
I have been working on that my self. I found pre cut 3" cd-r media at CDR Outlet They also have un-cut 3" disks if your realy brave. I just ordered some which the site says should ship in 2 days via ups ground not great for the shipping charges but I'm not ready to cut my own.
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xpsurvivalguide.pdf
Do you have any experience with Exim SMTP callouts or Sendmail BMilter SMTP callbacks. I think they look promising for several reasons.
d oc/html/spec_3 7.html#SECT37.10
They put some of the burden on the source of the mail. They raise the bar on spoofed sender addresses. I don't think they expose the carrier to content scanning issues as the session is blocked at the headers (I could be very wrong).
SMTP callbacks can be used to verify the following:
* RFC 821, MAIL FROM:
You are required to support a NULL return path according to RFC 821. Some people disable this either because they think it's cute or because they're trying to disable spam sent with a NULL return path. Irregardless, it's broken.
* RFC 822, RCPT TO:
Sites without Postmaster accounts are simply due to admin laziness or misconfiguration. According to RFC 822, you are required to accept mail for a few specific accounts, this is one of them.
* RCPT TO:
If the sender is unknown on the machine that answers for the domain used by the sender, then either a) the site is mis-configured or b) in all probability this is a spoofed email address and the email content is spam.
Exim Address verification
http://www.exim.org/exim-html-4.00/
BMilter
http://blue-labs.org/software/Bmilter/
Yes it does.
I was on the beta program and it rocks.
I just ordered some which the site says should ship in 2 days via ups ground not great for the shipping charges but I'm not ready to cut my own.
The description is as follows:
Same here. Consider it confirmed.