My servers have lots of resource and bandwidth that I can offer pop before smtp but I didn't because

- it will eat up more resources. I tell customers to use their isp's outgoing mail server so that they won't overwhelm my machine and network.
- it will cause me work harder when someone send spam, virus etc.

Unfortunately, few clients resell my hosting package to someone else and they don't wan't to explain their customers how to setup isp's smtp, they claim "customers change isp so often and I don't want to explain them when they can't send mail". To be optimistic, most newbies don't know how to setup smtp , will become more experience for 1-2 years , and know how to use isp's outgoing mail.

You should allow POP before SMTP as it doesn't allow SPAMMERS as easily.

If someone wants to spam, they are not going to do it that way, they will just use the binary, allowing pop before smtp, is fine, at least in my experience.

I'm afraid that clients will be spoiled by not trying to use their ISP's smtp server first ?

err, you save you have alot, but then you say it will eat up resources? Set it up, then if you want, at first give it to a few clients, it cant be that bad.

only thing about this is you must tell the clients to check their email BEFORE sending any email..

some email clients will send email first THEN check pop3.

I allow my clients to use pop before smtp because I don't want to go thru the hassle of telling my clients use your ISP's smtp servers what happends when the client is out of the area, what happends when the client is at work using the network etc..etc... and Since most of the e-mail clients are predefined to check before send I don't see it as a problem.

The bandwidth implications should be very minimal (certainly no more than a couple gigs if you have a few hundred customers). If your users were going to SPAM, they could do it through sendmail anyway, so it really doesn't make a difference.

I'd say go ahead and add it.