Aeria, usually, email, ftp , http is all counted. This means storage, traffic and all is all included. That's only fair. or like you mentioned, what if they send a 500mb file. Now, if it is all counted, you don't really have to bother. They are paying for it.
So does that mean you allow e-mail messages and e-mail storage up to 50mb? And let's say they have not retrieved that 50mb message and another 1mb message comes through, is that rejected because they are over their allotment?
I'm also thinking with the example given above, hypothetically saying thats all the traffic they had for the month, does that mean monthly transfer is now 100mb (50 in + 50 out + web traffic).
Wow, I don't no why I'm so confused (???), must be I need more coffee.
Yes. Basically the only restriction is bandwidth and storage. So assuming:
Case 1: They have used up their bandwidth allotment and still have storage
This depends on your policies. If you are more flexible, you may allow it through. If not, well, I guess it will be rejected. But this is going to be really complicated.
Case 2: They have lots of bandwidth left, but not enough space to contain the email being sent. This may lead to lost emails, depending on the email server I guess.
This will probably still be accepted but if your software controls the harddisk space, it will not be able to save it.
As fr your question, yes, it will be 100mb of traffic.
In general, limiting by space and bandwidth is good ways to limit their activity. As for the flexibility, it's always better to give them the space and monitor closely. Some months may be extraordinary and they may exceed by a bit. Clients typically are co-operative and a nicely worded email will get them to clean up their act. Unless it becomes a history of abuse or it becomes detrimental to your other clients.