number of email addresses in one email

How many contacts can I include on an email sent from Office 365?

 

The number of contacts allowed to include as recipients of an outgoing message in Office 365 depends upon the package you have subscribed to. You can always set up a distribution group if needed. By creating a distribution group, you can actually increase the number of recipients allowed by about 10 times, however, message size limits are strictly enforced for distribution groups.