In order to prevent spam, Google will temporarily disable accounts which send a lot of email in a short time. It's important to be aware of these limits when doing a mail merge. Here are the limits, from Google's help pages:
- 2,000 messages per day (i.e., you can hit 'Send' a maximum of 2,000 times)
- 500 unique recipients per message (external) or 2,000 (internal)
- 10,000 total recipients per day (for example, you could send 20 emails, each with 500 recipients)
In addition to these limitations, Google will temporarily disable your account if you exceed these limits or if you send a large number of undeliverable messages.
According to the Google help center, you can only send a message to up to 100 people at a time if you use POP or IMAP. For more detailed information, see Google's Support Page on Sending Limits.
If you don't need to customize content for your recipients, you can simply BCC them on an email. You can put your own (or your department's) address in the To field and paste the list of recipients into Bcc.
Connecting Outlook to Your Google Apps Account
You can continue to send mail merges using Outlook, but you must configure Outlook to connect to your GoogleApps account. Ask your department's IT support staff to help you set this up.
Using Scripts in a Google Spreadsheet
Using this tutorial, you can create a Google spreadsheet that sends a mail merge. The tutorial is slightly outdated, so it might help to have some foundational knowledge of Google Apps Script.
Mail Marketing Services
If you are sending large mailings or are contacting people for marketing purposes, alternate solutions such as the ones linked below are often the most appropriate way to contact your audience. They can have advantages such as the ability to send nicely-formatted HTML emails and track the success/open rate of your message. Before getting started with one of these, we recommend contacting Web Services for best practices and template suggestions.