We've recently moved our Exchange environment from on premise (Exchange 2007) into the cloud with Office 365, running a hybrid environment with an Exchange 2010 on premise server for internal scan-to-email MFPs, migrations & public folders.
We've also just found out that the owner of 1 particular system used to send maintenance emails to 1177 recipients. Since moving to Office 365, these emails have been rejected, because of the 500 recipient per email limit. This has caused the system owner to kick up and cause a real stink. We’ve suggested creating a distribution list, which is obviously best practice, which he maintains, (this caused another stink, toys got thrown out of prams etc).
Anyway, we can create the DL either on the cloud, or on premise. If we do it on the cloud, managing the DL via Outlook is slow, really really slow, took me about 5 to add 1 user. Creating on premise works a lot quicker, however I’m worried about what happens to the DL, when it’s expanded. i.e. if we send an email to an on premise DL with 1200 members, does it go from Outlook client > on premise Exchange 2010 server, the DL is expanded to 1200 recipients > cloud, where it might be rejected because it’s more than 500 users. Or does it get expanded when it hits the cloud, so the number of members isn’t a problem?