Size of contact list

Hi Pat Henderson,

A contact list with 29 members would not normally be considered too large. However, the applicable sending limit depends on the type of account added to new Outlook. For example, Outlook.com allows Microsoft 365 subscribers up to 500 recipients per message, while third-party accounts follow the email provider’s limits. Sending limits in Outlook.com | Microsoft Support 

Please note that this is a user-to-user forum, so contributors cannot access your account or examine the message delivery records. However, you can try these checks:

1. Create a new message, add the contact list to the To field, and check whether Outlook shows or expands all 29 recipients.
2. Open People > All contact lists, select the list, and choose Edit to confirm that all 29 addresses are still included and correct.
3. Send a separate test message directly to one affected address. If the direct message arrives, remove and add that contact again before retesting the list.

Could you confirm which type of account you are sending from, such as Outlook.com, Gmail, Yahoo, or another provider? Also, does Outlook return a non-delivery message, or do the recipients simply not see the email? Please remove any personal information before sharing the message.

I hope these checks help determine whether the issue is with the saved contact list or email delivery.

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