Your distribution list email can stop sending midway for two main reasons:
Outlook Attachments in Email Body
Attaching files directly in Outlook limits your maximum file size to 4MB when sending with ContactMonkey. When you attach files to the email body in Outlook rather than embedding them through ContactMonkey, it can cause sending failures.
Solution: Embed your attachments through the File Manager instead of attaching them directly in Outlook.
Microsoft Outlook Sending Limits
Microsoft imposes sending limits on each email address. When you send to large distribution lists using Individual tracking, Outlook may throttle or stop your send entirely.
Solution: If you regularly send to large distribution lists, contact your Customer Success Manager about Email at Scale. This feature allows you to send to over 10,000 recipients at significantly faster speeds and is available for Office 365 and Gmail customers.
What Happens When This Occurs
ContactMonkey's alert system automatically notifies both you and your Customer Success Manager when a distribution list send fails or stops midway. You'll receive an email alert showing whether your email was delivered successfully or encountered issues.