My Emails Come Slowly

Some emails are delayed to foil spammers and viruses.

Much spam and many viruses are delivered in such a way as to fail if treated this way. Real mail servers simply try again later. Spammers often do not retry because it would cost them more money and effort. Viruses often do not retry in order to remain hard to detect.

Briefly, it works by telling the connecting server to try again later. We keep track of the IP address and the sender. If that IP+sender pair try again later, we let the message in. Once an IP+sender successfully gets a message to you, we keep track of that success for a considerable period of time so later such messages are not delayed.

We allow Professional users to turn the service off and on, see some of the data under the hood and to blacklist and whitelist IP addresses and senders.

If you are interested in the technical details, see Evan Harris' paper on greylisting. We use a similar algorithm.