When composing and sending an email, our system doesn't allow you to select all contacts at once if you have more than 20 contacts. This forces fundraisers to review the addresses they are sending to.
When sending blast emails, if ISPs (such as Gmail, Yahoo, etc.) detect inactive and spamtrap email addresses among the bunch, they will flag the sender's address and filter future emails — even valid ones — to recipients' spam folders. To avoid this, we make fundraisers choose their emails, ensuring they are all current and accurate. In this way, emails will appear in the proper place, be viewed by their intended recipient, and hopefully will elicit the desired response.
We understand that fundraisers may have questions about such a limitation. We have therefore made it possible for administrators to message to their fundraisers about this limitation within the compose email interface. To add messaging for your fundraisers about the contact selection limitation, navigate to the Campaign Dictionary in your campaign's Admin Panel, and edit the entry titled "Page Text - Headquarters - Select Contacts Pop - Help Text". This text will be displayed in the "Add From Contact Book" popup accessible from the Email tab in the Fundraiser Dashboard, which is used to add recipients to an email.