I've got a domain name hosted with a webhost where any mail addressed to that domain is held up for 20 minutes if it is a new sender. This was explained to me when I called in to the support line and queried a number of such delays. Firstly, I don't understand why they would implement something like that. The mail gets sent anyway so what is the delay meant to achieve. Secondly, does anyone else have this problem with any mail servers? The reason I find it tedious is that I use that address for online registrations. That means that I have to sit and wait every time for the notification or confirmation mails to come through before I can continue.