On Thu, Sep 04, 2008 at 02:01:48PM +1200, Mark Foster wrote: > So in terms of the OP, > I don't see why joe-user on a dynamic-IP home connection should need the > ability to use port 25 to talk to anywhere but their local ISP SMTP server > on a normal basis[1].
Whats a normal basis? My Home ISP won't let me send to more than 200 (or so) email addresses per day. If I used my ISP's email system I would constantly be losing my email service due to hitting the limit. I do the field scheduling for my local town soccer league. [Never volunteer! :-) ] So when I send a few announcements out to coaches, referees and administrators, I hit that limit and get my email shutoff for two days or so. I eventually switched to MailHop at DynDNS (smtp auth) I would have used port 25 but our ISP has begun blocking outbound port 25 nationwide, due to large amount of outbound spam from their customers. :-) > Theyre not doing MX lookups so theyre not going > direct to remote MTAs[2]. Regardless of where they got the mail _from_, > the outbound mail should be via SMTP to their local SMTP server.[3] > > If you separate inbound (pop3) and outbound (smtp) mail delivery in your > thinking you can start to make sense of things (from a users perspective). > This is always the tack i've taken when trying to educate users about why > their email outbound doesn't work when theyre moving from ISP to ISP. > (At which point you offer them your authenticated-another-way service, > such as 587 with SMTP auth). > > [1] Customers with a specific need to do so should have the means to > opt-out. I believe most of the ISPs in NZ who block 25-outbound from > clients also offer this option. > > [2] Customers doing MX lookups are either drones or people with mail > servers at home. The former are obviously the target of the block. The > latter are likely going to be any one of: > > - Blocked by SORBS or similar as a dynamic IP > - Running a mail server in breach of AUP > - On a fixed IP and (theoretically) capable of securing their system and > not being a drone or open mail relay (and being traceable via their ISP). > > [3] Note also [2]. Outbound mail is associated with your ISP and their > SMTP service. Has nothing to do with inbound mail. Nothing. Nada. Zip. > > Or doesn't the rest of the world think like this? > > Mark. > > PS: It occurs to me that SPF has an influence here, if you're aggressively > using it then you should also be offering alternatives to Port 25 SMTP. > IMHO. > --
