Live@Edu: Updated Message and Recipient Limits
Just stumbled over this on a blog I've never seen before (some Education Partner site): Bit in bold is worth knowing because I've had folk legitimately hit the 500 limit e.g. Primary trying to mail parents/guardians to say the school might be closed, then is closed, then will likely be open tomorrow etc.
Outlook Live accounts have historically been 500 recipients per day. Microsoft has recently updated this policy to be in line with the Exchange Online offering in Office 365. All newly provisioned tenants will see these new limits immediately. For those customers who are already on Live@EDU, you should either see these now or you will see the changes over the upcoming weeks.
There is a recipient rate limit, often called a sender limit or sending limit, for cloud-based e-mail accounts. This limit defines the maximum number of recipients that can receive e-mail messages sent from a single cloud-based account in a 24-hour period. The recipient rate limit for Exchange Online is 1,500 recipients per day.
 Not in an announcement sent to Live@Edu tenancy Contact mailbox. Not on outlookliveanswers. Not on James Marshall's blog. Etc. The biggest problem I have with cloud-Exchange versus local Exchange is being aware of changes because there is no obvious single place you can go for the info. It's the biggest "cultural" difference from local where e.g. new SP comes out so you read what's new and know you've got that when you install it, or you go change some config and know you've done it.