I've also thought of SMTP as the ultimate queuing system. It really covers all of the bases for persistence, async delivery, bridges to every kind of network imaginable (think back to FidoNET, UUCP -- revive the bang path!), built in fault tolerance, etc.
The only thing really missing is delivery order guarantee. It isn't uncommon at all for a message to fail delivery, get stuffed into a retry bucket, and then a bunch of other messages get delivered without problem before the retry occurs. But even this is just an implementation issue. The underlying architecture is nearly perfect.
The only thing really missing is delivery order guarantee. It isn't uncommon at all for a message to fail delivery, get stuffed into a retry bucket, and then a bunch of other messages get delivered without problem before the retry occurs. But even this is just an implementation issue. The underlying architecture is nearly perfect.