Christopher Chan wrote:
That default setting is no longer applicable today. Users will scream if they find out that their mails have been sitting in the queue for a day. For today's businesses, one day can make or break a deal and so email, being a much faster form of communication than snail mail, has come to be seen as the preferred choice. People start calling when they know they are supposed to get an email in a minute or so when it does materialize.
So you never send any email to anyone using greylisting? thats odd, as its very common nowdays. greylisting servers will auto-reject the first attempt at sending an email, then accept it on a later retry (typically 10 or 15 minutes is the default retry interval for most mail servers). This /guarantees/ email will sit in your outbound queue for at least one retry interval.
I frequently run into outbound mail that sits in my queues for several hours, the destination servers may be too busy, or they may be offline for maintenance, many reasons. There's a k12 school district up in Chico CA who's mail server seems to be down as often as its up, and there are several folks on that server who subscribe to various email lists I host. the mail gets through eventually.
Email is /NOT/ IM. If your users expect it to function like Instant Messaging, maybe you should suggest they use IM when they want immediate response with feedback.