Server -> Client content updates

Im looking at methods to send multiple lists to many many objects in SL (and growing at a rate of several hundred objects a month).

Ive played with writing a server in SL and using email, but the processing delay and the volume of email requests are making it impractical - would end up with lots of servers, each stuffed to the gills with email slave scripts to get round the 20 second delay (and im not to thrilled about the potential impact on sim performance). On the plus side this solution does keep everything in SL. (well, aside from a single httprequest to get the server uuid)

Option 2 is send the email from an external php server, but I have some questions - How large an email can I practically send to a script (from any source), and is email from an external server to an in world object reliable?

Ive looked at http request, the delay and having to deal with pages makes it more complicated, ideally I would like to have an object request data and get one blob in return and thats it.

From the wikki-

address and subj are limited to 78 characters each.
message is limited to 1000 characters.

Seems like just posting your message to an external web server, then having your clients manually check that web server at a set interval would be a better solution to me. This would remove the dependency on the SL emails, which can have significant lag issues. And since you already need a timer to check the email in the first place, you might as well just check the external web server instead.

make sure that your web host does not use a built in latency called "tarpitting"...that is the limiting of the number of emails it will forward in a certain time period...this is done to prevent the use of the host as a conduit for large volume email spamming. Some hosts will do this, some dont...but it is worth asking about, before you reach a point where you have failures. My own hosting company limits relaying emails to 25/minute....so when I tried using HTTPRequest to send data with some web based scripts, it started failing when I reached that saturation point.

I have the luxury of my own server, so I dont have to worry to much.

Wikki is inaccurate - in my testing addy is limited to 78, subject is 256, and body is 4096.