YM wrote:
Hi Bill,
Thanks Bill.
How do I block my users to put <> or invalid From: address in their outgoing
emails? Using /var/qmail/control/badmailfrom or ?
That would be one way I believe.. Another is to force SMTP Auth.. It doesn't fix the bad From: address, but it will tag the email with an authoritative header on who sent it.. :)
Secondly, what is the effect of SPF to end users?
SPF ... Well, in a nutshell, when you are checking SPF with the default setting (a 3 in spfbehavior), it will look for an SPF record for the domain in the From: header. If there is none, the mail is passed on as if nothing happened. If there is a record, then one of two things happens. If the record indicates that the email could have originated from the mailserver that's sending it, it's passed on as normal. If the record indicates that the sending mailserver is not allowed to send mail for that domain, then it rejects the mail.
So, in essence, it will only affect the end user if they are trying to receive mail from someone who is incorrectly sending the mail from a non-authoritative server. There is no effect on sending mail, unless you have published an SPF record for your domain. I suggest checking out http://spf.pobox.com for more detailed information.
Personally I think SPF is nice and will help, assuming the majority of mailservers publish SPF records...
-- --------------------------- Jason 'XenoPhage' Frisvold Engine / Technology Programmer [EMAIL PROTECTED] RedHat Certified - RHCE # 803004140609871 MySQL Pro Certified - ID# 207171862 MySQL Core Certified - ID# 205982910 --------------------------- "Something mysterious is formed, born in the silent void. Waiting alone and unmoving, it is at once still and yet in constant motion. It is the source of all programs. I do not know its name, so I will call it the Tao of Programming."
