> Sorry about the spam. Huh?
> Got the answer from > http://www.ipswitch.com/support/IMail/guide/imailug7/security4.html No, you didn't. > Refuse NULL <> Senders. If enabled, IMail Server refuses to accept > mail if there is no address specified in the MAIL FROM line of an > incoming message (the null address (<>) is used). Allowing no > address in the MAIL FROM line makes it easier for spam mailers to > send bulk mail to your users. However, note that RFC 822 requires > that mail servers accept mail that has no address in the FROM line. This has nothing to do with your original question. Your original request is addressed by the 'Check valid sender' option. DO NOT CHECK 'Refuse NULL <> Senders' if you want to run your mail server responsibly. You must be allowed to get DSNs, or managing and troubleshooting mail flow will be impossible. > Note that Microsoft Exchange uses the null address for messages from > the postmaster, so selecting this option disables the ability of > IMail Server users to receive mail from Exchange postmasters... ...as well as from any other RFC-compliant mailservers. There is actually a blacklist--seldom used to date, but hopefully someday--called RFC-Ignorant (www.rfc-ignorant.org) dedicated to people who break the RFCs by not allowing <>/null senders to send mail, as well as other types of RFC disobedience. There is no practical reason to *not* allow <>/null senders to use your server. It will break many, many things, and fix essentially none. Write back if you have further questions. Sandy Please visit http://www.ipswitch.com/support/mailing-lists.html to be removed from this list. An Archive of this list is available at: http://www.mail-archive.com/imail_forum%40list.ipswitch.com/ Please visit the Knowledge Base for answers to frequently asked questions: http://www.ipswitch.com/support/IMail/
