Not sure if this has appeared here earlier, but I think various people had in the past proposed knocking up a website where one would enter the details of the flight, and it would advise the correct authorities.
Some of these were contactable only by fax (still the case IIRC for most of Special Branch) so such a website would have involved a prepay account to finance the fax costs.
If one can do all notifications by email, the need for prepay disappears.
It is then also incidentally less important to be correctly selective on "over-notifying" e.g. some pilots already send the GAR to all 3 services for every foreign flight, using a batch script 
A nice feature would be to store personal details for recalling on repeat flights but that gets you hassles with the DPA
My recollection was that the principal issue which would remain is a liability for a failure to deliver the notification. This is still present if you use email, but I suppose one could circumvent that adequately by ensuring the email was apparently delivered (which is easy), BCCing it to yourself (the site owner) and then emailing a copy of the BCCs (with headers & all) to the filing pilot. You also have to hope that no force has silly spam filters...
The problem is that Special Branch in particular, as I know too well, can get exceedingly anal about this. On one occassion their fax was not working (no paper?) so I faxed the GAR to a neighbouring force, and got a 4am call giving me a bollocking; the officer was completely uninterested in their duff fax machine as that was clearly
my responsibility
So one might expect to get a little bit of flak here and there
So what is happening to Martello's project? When I spoke face to face to the Borders people a year or two ago, they were going to set up a website which would do the lot, and it would be "official".