For security reasons, a limitation of sending no more than 1000 emails/recipients per day and no more than 500 emails/recipients within an hour is in place for all students faculty and staff. This limit exists to stop bulk malicious email from accounts taken over by malware or scammers.  This parameter was set after careful analysis to avoid disrupting normal day-to-day use of email.  Additionally, something to be aware of is that Microsoft has its own sending limit of 30 emails per minute.  If you are sending to more than 30 recipients, mail delivery may be delayed to some of the recipients.

Bulk emails or meeting invites - When sending an email to approximately 100 or more individuals, an email list should be used. DotCIO provides Sympa as an email list solution. Please refer to the Sympa article to assist in list creation, management and subscription.  

Bulk emails requiring Mail merges – Many offices also use MailChimp as an emailing solution for bulk emails.  Mail Chimp cannot be used for meeting invites but it can be used for mail merges if you want a more personalized email than a sympa list can provide. Mailchimp is free for up to 500 recipients.

If you have any questions on this or need assistance with Sympa lists, please submit a Support Request at https://itssc.rpi.edu